Automatic Shelf Registration Statement (Form S-3ASR)

As filed with the Securities and Exchange Commission on June 3, 2026

Registration No. 333-     

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

AEVA TECHNOLOGIES, INC.

(Exact name of registrant as specified in its charter)

555 Ellis Street

Mountain View, CA 94043

(650) 481-7070

(Address, including zip code, and telephone number, including area code, of registrant's principal executive offices)

Soroush Salehian Dardashti

Chief Executive Officer

Aeva Technologies, Inc.

555 Ellis Street

Mountain View, CA 94043

(650) 481-7070

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Approximate date of commencement of proposed sale to the public: From time to time after the effective date of this Registration Statement.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box. ☐

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box. ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box. ☒

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company" and "emerging growth company" in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

PROSPECTUS

Common Stock

Preferred Stock

Debt Securities

Warrants

Up to 3,509,719 shares of common stock offered by the selling stockholder

Shares of common stock offered by additional selling stockholders

We may offer and sell from time to time, in one or more offerings, in amounts, at prices and on terms determined at the time of any such offering, (1) shares of our common stock, (2) shares of our preferred stock, which we may issue in one or more series, (3) debt securities, which may be senior debt securities or subordinated debt securities, or (4) warrants to purchase our common stock.

In addition, this prospectus relates to the offer and potential resale from time to time of (1) up to 3,509,719 shares of our common stock (the "resale shares") held by a selling stockholder (together with its permitted transferees, the "selling stockholder") in amounts, at prices, and on terms that will be determined at the time of the applicable offering and (2) shares of our common stock held by selling stockholders to be named later (the "additional selling stockholders"). The selling stockholder acquired the resale shares from us pursuant to a subscription agreement dated May 13, 2025. We issued the resale shares to the selling stockholder in reliance upon the exemption from registration afforded by Section 4(a)(2) of the Securities Act of 1933, as amended (the "Securities Act"). Our registration of the shares offered by the selling stockholder or any additional selling stockholder does not mean that such selling stockholder or additional selling stockholder will offer or sell any shares of our common stock. We will not receive any of the proceeds from the sale of our common stock by the selling stockholder or any additional selling stockholder. The selling stockholder and any additional selling stockholder will bear all discounts, concessions, commissions and stock transfer taxes, if any, attributable to its sales of shares of our common stock.

Each time we or any additional selling stockholders sell shares of our common stock, we or such additional selling stockholders will provide the specific terms of the offering, and, if applicable, the additional selling stockholders, in a supplement to this prospectus. This prospectus provides you with a general description of the securities we may offer. The securities may be offered by us at prices and on terms determined at the time of offering. We may also authorize one or more free writing prospectuses to be provided to you in connection with such offerings. The prospectus supplement and any related free writing prospectus may add, update or change information contained in this prospectus. You should carefully read this prospectus, the applicable prospectus supplement and any related free writing prospectus, as well as the documents incorporated by reference herein and therein, before you invest in the securities described in this prospectus.

We, the selling stockholder or any additional selling stockholder may offer and sell the securities described in this prospectus and any prospectus supplement separately or together sale through underwriters, dealers or agents, or directly to purchasers, or through a combination of these methods. See "Plan of Distribution" beginning on page 8 of this prospectus. If any underwriters, dealers or agents are involved in the sale of these securities we will set forth their names and describe their compensation in the applicable prospectus supplement.

Our common stock, $0.0001 par value per share, is listed on The Nasdaq Global Select Market ("Nasdaq") under the symbol "AEVA." On June 2, 2026, the closing price of our common stock was $27.76 per share.

Investing in our securities involves risks. See the section of this prospectus captioned "Risk Factors" beginning on page 5, as well as in any applicable prospectus supplement and in our Securities and Exchange Commission ("SEC") filings that are incorporated by reference herein.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

This prospectus may not be used to sell securities unless accompanied by a prospectus supplement.

The date of this prospectus is June 3, 2026

TABLE OF CONTENTS

i

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus, any prospectus supplement, and the information incorporated by reference in this prospectus and any prospectus supplement contain or may contain forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the "Securities Act"), and Section 21E of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), which statements involve substantial risk and uncertainties. All statements contained in this prospectus other than statements of historical fact, including statements regarding our future results of operations and financial position, our business strategy and plans, and our objectives for future operations, are forward-looking statements. The words "believe," "may," "will," "estimate," "continue," "anticipate," "goal," "plan," "intend," "expect," "seek", and similar expressions are intended to identify forward-looking statements. We have based these forward-looking statements largely on our current expectations and projections about future events and trends. These forward-looking statements are subject to a number of risks, uncertainties and assumptions, including our history of losses, and limited sales; the risk our programs are not fully developed and commercialized, or if such programs experience significant delays; our limited operating history; the risk that our strategic initiatives designed to grow our business, including our selection by a top European passenger original equipment manufacturer and our strategic collaboration with LG Innotek Co., Ltd., may not be successful or may prove more costly than we currently anticipate; the risk our products are not selected for inclusion in development programs for assisted driving systems or autonomous driving systems , industrial automation, consumer device, robotics and security applications, or are not adopted by customers; the lengthy period of time from a design win to implementation, and the risks of cancellation or postponement of the contract or unsuccessful implementation; the risk our forward looking estimates of certain financial metrics, including but not limited to Order Book, may prove inaccurate; the risk that we may be unable to effectively manage our supply chain; the risk that the complexity of our products could result in unforeseen delays or expenses from undetected defects, errors or reliability issues in hardware or software which could reduce the market adoption of new products, damage our reputation with current or prospective customers, expose Aeva to product liability and other claims and adversely affect our operating costs; continued pricing pressures, automotive original equipment manufacturer ("OEM") cost reduction initiatives and the ability of automotive OEMs to re-source or cancel vehicle or technology programs; the risks relating to incurring substantial R&D costs and devoting significant resources to identifying and commercializing new products; uncertainty related to the market adoption of LiDAR, including Aeva's 4D LiDAR technology; the risk our transition to an outsourced manufacturing business model may not be successful; risks related to product liability or warranty claims that could result in significant direct or indirect costs to us; the risk of our high dependence on the services of Soroush Salehian Dardashti and Mina Rezk, our two founders; the potential interruption or failure of our information technology and communication systems and cybersecurity risks to our operational systems, security systems, infrastructure, integrated software in our LiDAR solutions and those risks described under "Risk Factors" of this prospectus, any prospectus supplement that we may file, and in any Annual Report on Form 10-K and any Quarterly Report on Form 10-Q incorporated by reference in this prospectus or any prospectus supplement. Moreover, we operate in a very competitive and rapidly changing environment. New risks emerge from time to time. It is not possible for our management to predict all risks, nor can we assess the impact of all factors on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements we may make. In light of these risks, uncertainties and assumptions, the future events and trends discussed in this prospectus may not occur and actual results could differ materially and adversely from those anticipated or implied in the forward-looking statements.

You should not rely upon forward-looking statements as predictions of future events. The forward-looking statements contained in this prospectus, any prospectus supplement, the information incorporated by reference in this prospectus or any prospectus supplement, or any free writing prospectus we may authorize are based on information currently available to us and expectations and assumptions that we deem reasonable at the time the statements were made. We do not undertake any obligation to update any forward-looking statements in this prospectus, any prospectus supplement, including the information incorporated by reference in this prospectus or any prospectus supplement, any free writing prospectus we may authorize or in any of our other communications,

1

except as required by law. Such forward-looking statements are subject to risks, uncertainties (some of which are beyond our control) and other important factors that could cause actual results and the timing of certain events to differ materially from future results expressed or implied by such forward-looking statements. All such forward-looking statements should be read as of the time the statements were made and with the recognition that these forward-looking statements may not be complete or accurate at a later date.

2

ABOUT THIS PROSPECTUS

This prospectus is part of an automatic registration statement that we filed with the Securities and Exchange Commission (the "SEC") as a "well-known seasoned issuer" as defined in Rule 405 under the Securities Act of 1933, as amended (the "Securities Act"), utilizing a "shelf" registration process. Under this shelf registration process, we may offer and sell any combination of the securities described in this prospectus from time to time in one or more offerings, and the additional selling stockholders to be named in a supplement to this prospectus may offer and sell shares of our common stock from time to time in one or more offerings as described in this prospectus. The selling stockholder may use the shelf registration to sell up to 3,509,719 shares of common stock from time to time through any means described in the section titled "Plan of Distribution."

You should rely only on the information contained in this prospectus (as supplemented and amended), including the information incorporated by reference, or any free writing prospectus we may authorize. We and/or the selling stockholder provided the information contained in the aforementioned documents only as of the date of the applicable document, and it is possible that the information, including our business, financial condition, and results of operations, may have changed since that date.

This prospectus only provides you with a general description of the securities that we, the selling stockholder and/or any additional selling stockholder may offer. Each time we and/or any additional selling stockholder sell securities pursuant to this prospectus, we and/or such additional selling stockholder will provide a prospectus supplement that contains specific information about the terms of the offering, including the specific amounts and prices of the securities offered. In addition, the prospectus supplement may also add, update or change the information contained in this prospectus. If this prospectus is inconsistent with the prospectus supplement, you should rely upon the prospectus supplement.

We urge you to read carefully this prospectus (as supplemented and amended) before deciding whether to purchase the common stock being offered.

Neither we or the selling stockholder have authorized anyone to provide any information other than that contained or incorporated by reference in this prospectus or in any free writing prospectus prepared by or on behalf of us or to which we have referred you. Neither we nor the selling stockholder take any responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. Neither we nor the selling stockholder are making an offer of our securities in any state where the offer is not permitted. You should not assume that the information contained in or incorporated by reference in this prospectus or any prospectus supplement or in any such free writing prospectus is accurate as of any date other than their respective dates.

Unless the context otherwise requires, the terms "Aeva," "we," "us," "our," and "the Company" mean Aeva Technologies, Inc. and its subsidiaries.

3

AEVA TECHNOLOGIES, INC.

Overview

Our vision is to bring perception to broad applications. Through our Frequency Modulated Continuous Wave ("FMCW") sensing technology, we believe we are introducing the world's first 4D LiDAR-on-chip that, along with our proprietary software applications, have the potential to enable the adoption of LiDAR across broad applications.

Founded in 2017 by former Apple engineers Soroush Salehian and Mina Rezk and led by a multidisciplinary team of engineers and operators experienced in the field of sensing and perception, Aeva's mission is to bring the next wave of perception technology to broad applications from automated driving, manufacturing automation and smart infrastructure, robotics and consumer devices. Our 4D LiDAR-on-chip combines silicon photonics technology that is proven in the telecom industry with precise instant velocity measurements and long-range performance for commercialization.

Unlike legacy 3D LiDAR, which relies on Time-of-Flight ("ToF") technology and measures only depth and reflectivity, Aeva's solution leverages a proprietary FMCW technology to measure velocity in addition to depth, reflectivity and inertial motion. We believe the ability of Aeva's solution to measure instant velocity for every pixel is a major advantage over ToF-based sensing solutions. Furthermore, Aeva's technology is free from interference from other LiDAR and sunlight, and our core innovations within FMCW are intended to enable vehicles to see at significantly higher distances of up to 500 meters.

We believe the advantages of our 4D LiDAR-on-chip allow us to provide the first LiDAR solution that is fully integrated onto a chip with superior performance at scale, with the potential to enable higher level of automation for vehicles and the potential to drive new categories of perception across industrial automation, consumer device applications, and security markets.

Corporate Information

Aeva Technologies, Inc. was originally incorporated in Delaware as a special purpose acquisition company on August 16, 2019 under the name InterPrivate Acquisition Corp. ("IPV"). On March 12, 2021, the Company consummated a business combination (the "Business Combination") with Aeva, Inc. In connection with the consummation of the Business Combination, the Company changed its name from IPV to Aeva Technologies, Inc. The Company's common stock is listed on the Nasdaq Global Select Market under the symbol "AEVA".

Aeva is a Delaware corporation. Our principal offices are located at 555 Ellis Street, Mountain View, CA 94043, and our telephone number is (650) 481-7070. Our website address is https://www.aeva.com. Information contained on or accessible through our website is not part of this prospectus and is not incorporated by reference herein.

4

RISK FACTORS

Investing in our securities involves a high degree of risk. Before deciding whether to purchase our securities, you should consider carefully the risks and uncertainties discussed under the section titled "Risk Factors" contained in our most recent Annual Report on Form 10-K, as updated by our subsequent Quarterly Reports on Form 10-Q and other filings we make with the SEC, which are incorporated by reference into this prospectus in their entirety, together with other information in this prospectus and the documents incorporated by reference. The risks described in these documents are not the only ones we face, but those that we consider to be material. There may be other unknown or unpredictable economic, business, competitive, regulatory, or other factors that could have material adverse effects on our future results. Past financial performance may not be a reliable indicator of future performance, and historical trends should not be used to anticipate results or trends in future periods. If any of these risks actually occurs, our business, financial condition, results of operations, or cash flow could be seriously harmed. This could cause the trading price of our common stock to decline, resulting in a loss of all or part of your investment. Please also read carefully the section above titled "Special Note Regarding Forward-Looking Statements."

Sales of a substantial number of our securities in the public market by the selling stockholder or by our other existing stockholders could cause the price of our common stock to fall.

Sales of a substantial number of shares of our common stock in the public market could occur at any time.

The selling stockholder can sell, under this prospectus, up to 3,509,719 shares, representing approximately a 5.6% beneficial ownership interest of our common stock as of March 31, 2026. Sales of a substantial number of our shares of common stock in the public market by the selling stockholder or by our other existing securityholders, or the perception that those sales might occur, could depress the market price of our common stock and could impair our ability to raise capital through the sale of additional equity securities. We are unable to predict the effect that such sales may have on the prevailing market price of our common stock. The sale of all the securities being offered in this prospectus could result in a significant decline in the public trading price of our securities. In addition, the registration of these shares of common stock for resale creates the possibility of a significant increase in the supply of our common stock in the market. The increased supply, coupled with the potential disparity in purchase prices, may lead to heightened selling pressure, which could negatively affect the public trading price of our common stock.

5

USE OF PROCEEDS

We intend to use the net proceeds from the sale of securities as set forth in the applicable prospectus supplement.

We will not receive any proceeds from the sale of the securities by the selling stockholder or any additional selling stockholder, but in certain cases we may pay fees and expenses relating to the registration or an offering of such securities, such as registration and filing fees, fees and expenses for complying with federal and state securities laws and Nasdaq rules and regulations, and fees and expenses incurred in connection with a listing, if any, of any of the securities on any securities exchange or association.

6

ADDITIONAL SELLING STOCKHOLDERS

Additional selling stockholders are persons or entities that, directly or indirectly, have acquired, or will from time to time acquire from us, our securities. Such additional selling stockholders may be parties to registration rights agreements with us, or we otherwise may have agreed or agree to register their securities for resale. The term "additional selling stockholders" includes donees, pledgees, transferees, distributees or other successors-in-interest selling shares of our common stock or interests in our common stock received after the date of this prospectus from an additional selling stockholder as a gift, pledge, partnership distribution or other transfer.

Information about additional selling stockholders, where applicable, will be set forth in a prospectus supplement, in an amendment to the registration statement of which this prospectus is a part, or in filings we make with the SEC under the Exchange Act, which are incorporated by reference.

7

PLAN OF DISTRIBUTION

We may, from time to time, sell the securities offered through this prospectus in primary offerings on any stock exchange, market or trading facility on which our securities are traded or quoted or in private transactions. The selling stockholder or any additional selling stockholder may, from time to time, sell, transfer, distribute or otherwise dispose of certain of its shares of common stock or interests in our common stock on any stock exchange, market or trading facility on which shares of our common stock are traded or in private transactions. The common stock may be distributed at a fixed price or prices, which may be changed, market prices prevailing at the time of sale, prices related to the prevailing market prices, or negotiated prices.

As used in this section, the term "selling stockholders" includes donees, pledgees, transferees, distributees or other successors-in-interest selling shares of our common stock or interests in our common stock received after the date of this prospectus from the selling stockholder or any additional selling stockholder as a gift, pledge, partnership distribution or other transfer.

We or the selling stockholders may use any one or more of the following methods when selling or otherwise disposing of the securities offered by this prospectus:

A selling stockholder that is an entity may elect to make an in-kind distribution of common stock to its members, partners or stockholders pursuant to the registration statement of which this prospectus is a part by delivering a prospectus, as amended or supplemented. To the extent that such transferees are not affiliates of ours, such transferees will receive freely tradable shares of common stock pursuant to the distribution effected through this registration statement.

Each time that we or any of the selling stockholders sell securities covered by this prospectus, we or the selling stockholders will provide a prospectus supplement or supplements that will describe the method of distribution and set forth the terms and conditions of the offering, including:

8

Sale through underwriters or dealers

If underwriters are used in a sale by us or a selling stockholder, the underwriters will acquire the securities for their own account, including through underwriting, purchase, security lending or repurchase agreements with us. The underwriters may resell the securities from time to time in one or more transactions, including negotiated transactions. Underwriters may sell the common stock in order to facilitate transactions in any of our other securities (described in this prospectus or otherwise), including other public or private transactions and short sales. Underwriters may offer securities to the public either through underwriting syndicates represented by one or more managing underwriters or directly by one or more firms acting as underwriters. Unless otherwise indicated in the applicable prospectus supplement, the obligations of the underwriters to purchase the securities will be subject to certain conditions, and the underwriters will be obligated to purchase all the offered common stock if they purchase any of them. The underwriters may change from time to time any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers. The applicable prospectus supplement will include the names of the principal underwriters, the respective amount of the securities underwritten, the nature of the obligation of the underwriters to take the securities and the nature of any material relationship between an underwriter, us and any selling stockholder.

If dealers are used in the sale of securities offered through this prospectus, we or a selling stockholder will sell the securities to them as principals. They may then resell the securities to the public at varying prices determined by the dealers at the time of resale. The applicable prospectus supplement will include the names of the dealers and the terms of the transaction.

The selling stockholder and any underwriters, broker-dealers or agents that participate in the sale of our securities or interests therein may be "underwriters" within the meaning of Section 2(11) of the Securities Act. Any discounts, commissions, concessions or profit they earn on any resale of shares of our securities may be underwriting discounts and commissions under the Securities Act. If a selling stockholder is an "underwriter" within the meaning of Section 2(11) of the Securities Act, then the selling stockholder will be subject to the prospectus delivery requirements of the Securities Act. Underwriters and their controlling persons, dealers and agents may be entitled, under agreements entered into with us and the selling stockholders, to indemnification against and contribution toward specific civil liabilities, including liabilities under the Securities Act.

Direct sales and sales through agents

We or a selling stockholder may sell the securities offered through this prospectus directly. In this case, no underwriters or agents would be involved. Such common stock may also be sold through agents designated from time to time. The applicable prospectus supplement will name any agent involved in the offer or sale of the offered securities and will describe any commissions payable to the agent by us. Unless otherwise indicated in the applicable prospectus supplement, any agent will agree to use its reasonable best efforts to solicit purchases for the period of its appointment.

9

We or a selling stockholder may sell the securities directly to institutional investors or others who may be deemed to be underwriters within the meaning of the Securities Act with respect to any sale of those common stock. The terms of any such sales will be described in the applicable prospectus supplement.

Selling stockholders also may resell a portion of our common stock in open market transactions in reliance upon Rule 144 under the Securities Act, provided that they meet the criteria and we and they conform to the requirements of that rule, or pursuant to other available exemptions from the registration requirements of the Securities Act.

Selling stockholders may, from time to time, pledge or grant a security interest in some shares of our common stock owned by them and, if a selling stockholder defaults in the performance of its secured obligations, the pledgees or secured parties may offer and sell such shares of common stock from time to time, under this prospectus, or under an amendment or supplement to this prospectus amending the list of the selling stockholders to include the pledgee, transferee or other successors in interest as the selling stockholders under this prospectus. The selling stockholders also may transfer shares of our common stock in other circumstances, in which case the transferees, pledgees or other successors in interest will be the selling beneficial owners for purposes of this prospectus.

Delayed delivery contracts

If the applicable prospectus supplement indicates, we or a selling stockholder may authorize agents, underwriters or dealers to solicit offers from certain types of institutions to purchase common stock at the public offering price under delayed delivery contracts. These contracts would provide for payment and delivery on a specified date in the future. The contracts would be subject only to those conditions described in the applicable prospectus supplement. The applicable prospectus supplement will describe the commission payable for solicitation of those contracts.

Stabilization and other transactions

Any underwriter we use in the sale of offered securities may engage in stabilizing transactions, syndicate covering transactions and penalty bids in accordance with Rule 104 under the Exchange Act. Stabilizing transactions involve bids to purchase the underlying security in the open market for the purpose of pegging, fixing or maintaining the price of the securities. Syndicate covering transactions involve purchases of the securities in the open market after the distribution has been completed in order to cover syndicate short positions.

Penalty bids permit the underwriters to reclaim a selling concession from a syndicate member when the securities originally sold by the syndicate member are purchased in a syndicate covering transaction to cover syndicate short positions. Stabilizing transactions, syndicate covering transactions and penalty bids may cause the price of the securities to be higher than it would be in the absence of the transactions. The underwriters may, if they commence these transactions, discontinue them at any time.

Derivative transactions and hedging

We, a selling stockholder, the underwriters or other agents may engage in derivative transactions involving our securities. These derivatives may consist of short sale transactions and other hedging activities. The underwriters or agents may acquire a long or short position in the securities, hold or resell securities acquired and purchase options or futures on the securities and other derivative instruments with returns linked to or related to changes in the price of the securities. In order to facilitate these derivative transactions, we may enter into security lending or repurchase agreements with the underwriters or agents. The underwriters or agents may effect the derivative transactions through sales of the common stock to the public, including short sales, or by lending the common stock in order to facilitate short sale transactions by others. The underwriters or agents may also use the securities purchased or borrowed from us or others (or, in the case of derivatives, common stock received from us in settlement of those derivatives) to directly or indirectly settle sales of the securities or close out any related open borrowings of the securities.

10

Electronic auctions

We may also make sales through the Internet or through other electronic means. Since we may from time to time elect to offer securities directly to the public, with or without the involvement of agents, underwriters or dealers, utilizing the Internet or other forms of electronic bidding or ordering systems for the pricing and allocation of such securities, you should pay particular attention to the description of that system we will provide in a prospectus supplement.

Such electronic system may allow bidders to directly participate, through electronic access to an auction site, by submitting conditional offers to buy that are subject to acceptance by us, and which may directly affect the price or other terms and conditions at which such securities are sold. These bidding or ordering systems may present to each bidder, on a so-called "real-time" basis, relevant information to assist in making a bid, such as the clearing spread at which the offering would be sold, based on the bids submitted, and whether a bidder's individual bids would be accepted, prorated or rejected.

Upon completion of such an electronic auction process, securities will be allocated based on prices bid, terms of bid or other factors. The final offering price at which common stock would be sold and the allocation of common stock among bidders would be based in whole or in part on the results of the Internet or other electronic bidding process or auction.

11

DESCRIPTION OF SECURITIES

This prospectus contains a summary of our capital stock, and the preferred stock, debt securities, and warrants that may be issued in the future. These summaries are not meant to be a complete description of each security. The particular terms of any security to be issued pursuant hereto will be set forth in a related prospectus supplement. This prospectus and the accompanying prospectus supplement will contain the material terms and conditions for each security.

12

DESCRIPTION OF CAPITAL STOCK

The following summary of the material terms of our capital stock is not intended to be a complete summary of the rights and preferences of such securities. Because it is only a summary, it may not contain all the information that is important to an investor in our securities. Defined terms used and not defined herein shall have the meaning ascribed to such terms in our Annual Report on Form 10-K. We urge you to read our Second Amended and Restated Certificate of Incorporation ("Certificate of Incorporation") in its entirety for a complete description of the rights and preferences of our capital stock.

Our Certificate of Incorporation authorizes the issuance of 422,000,000 shares of common stock, $0.0001 par value per share and 10,000,000 shares of preferred stock, $0.0001 par value. The following description of our capital stock does not purport to be complete and is subject to, and qualified in its entirety by, our Certificate of Incorporation and amended and restated bylaws, each of which is incorporated by reference as an exhibit to our Annual Report on Form 10-K.

Common Stock

Voting Power

Except as otherwise required by law or as otherwise provided in any Preferred Stock Designation, the holders of the common stock possess all voting power for the election of our directors and all other matters submitted to a vote of stockholders of ours. Holders of the common stock have one vote in respect of each share of stock held by such holder on matters to be voted on by stockholders. Except as otherwise required by law, holders of the common stock, as such, are not be entitled to vote on any amendment to the Certificate of Incorporation (including any resolutions adopted by our Board of Directors approving the issue of preferred stock (a "Preferred Stock Designation")) that relates solely to the rights, powers, preferences or other terms of one or more outstanding series of our preferred stock if the holders of such affected series of our preferred stock are entitled to vote on such amendment pursuant to the Certificate of Incorporation (including any Preferred Stock Designation) or pursuant to the Delaware General Corporation Law (the "DGCL").

Dividends

Subject to applicable law and the rights and preferences of any holders of any outstanding series of preferred stock of the Company, holders of the common stock are entitled to receive dividends when, as and if declared by our Board of Directors, payable either in cash, in property or in shares of capital stock.

Liquidation, Dissolution and Winding Up

Upon our liquidation, dissolution or winding up and after payment in full of all amounts required to be paid to creditors and to any holders of our preferred stock having liquidation preferences, if any, the holders of the common stock are entitled to receive pro rata our remaining assets available for distribution.

Preemptive or Other Rights

Subject to the preferential rights of any other class or series of stock, all shares of common stock have equal dividend, distribution, liquidation and other rights, and have no preference or appraisal rights, except for any appraisal rights provided by the DGCL. Furthermore, holders of common stock have no preemptive rights and there are no conversion, sinking fund or redemption rights, or rights to subscribe for any of our securities. The rights, powers, preferences and privileges of holders of the common stock are subject to those of the holders of any shares of our preferred stock that our Board of Directors may authorize and issue in the future.

Election of Directors

Our Board of Directors is divided into three classes, each of which generally serve for a term of three years with only one class of directors being elected in each year. There is no cumulative voting with respect to the election

13

of directors, with the result that the holders of more than 50% of the shares voted for the election of directors can elect all of the directors.

Classified Board of Directors

Our Certificate of Incorporation provides that our Board of Directors is divided into three classes of directors, with the classes to be as nearly equal in number as possible, and with each director serving a three-year term. As a result, approximately one-third of our Board of Directors is elected each year. The classification of directors has the effect of making it more difficult for stockholders to change the composition of our Board of Directors.

Authorized but Unissued Shares

The authorized but unissued shares of common stock and preferred stock are available for future issuance without stockholder approval, subject to any limitations imposed by the listing standards of Nasdaq. These additional shares may be used for a variety of corporate finance transactions, acquisitions and employee benefit plans. The existence of authorized but unissued and unreserved common stock and preferred stock could make more difficult or discourage an attempt to obtain control of us by means of a proxy contest, tender offer, merger or otherwise.

Stockholder Action; Special Meetings of Stockholders

Our Certificate of Incorporation provides that stockholders may not take action by written consent, but may only take action at annual or special meetings of stockholders. As a result, a holder controlling a majority of our capital stock would not be able to amend our Bylaws or remove directors without holding a meeting of stockholders called in accordance with our Bylaws. This restriction does not apply to actions taken by the holders of any series of preferred stock of ours to the extent expressly provided in the applicable Preferred Stock Designation. Further, our Certificate of Incorporation provides that, subject to any special rights of the holders of preferred stock, only our Board of Directors, the chairperson of our Board of Directors or the chief executive officer of the Company's may call special meetings of stockholders, thus prohibiting a holder of our common stock from calling a special meeting. These provisions might delay the ability of stockholders to force consideration of a proposal or for stockholders controlling a majority of our capital stock to take any action, including the removal of directors.

Advance Notice Requirements for Stockholder Proposals and Director Nominations

Our Bylaws provide that stockholders seeking to bring business before our annual meeting of stockholders, or to nominate candidates for election as directors at its annual meeting of stockholders, must provide timely notice. To be timely, a stockholder's notice will need to be delivered to, or mailed and received at, our principal executive offices not less than 90 days nor more than 120 days prior to the one-year anniversary of the preceding year's annual meeting, except in the case of a special meeting to nominate candidates for election as directors, timely notice shall not less than the later of 90 days prior to the special meeting or the 10th day following the day on which public disclosure of the date of the special meeting is first made by us). In the event that the date of the annual meeting is more than 30 days before or more than 60 days after such anniversary date, to be timely, a stockholder's notice must be so delivered, or mailed and received, not later than the 90th day prior to such annual meeting or, if later, the 10th day following the day on which public disclosure of the date of such annual meeting was first made by us. Our Bylaws also specify certain requirements as to the form and content of a stockholders' notice. These provisions may preclude our stockholders from bringing matters before its annual meeting of stockholders or from making nominations for directors at its annual meeting of stockholders.

Amendment of Charter or Bylaws

Our Bylaws may be amended or repealed by our Board of Directors or by the affirmative vote of the holders of at least 66²/₃% of the voting power of all of the shares of our capital stock entitled to vote in the election of

14

directors, voting as one class. The affirmative vote of the holders of at least 66²/₃% of the voting power of the then outstanding shares of our capital stock entitled to vote generally in the election of directors, voting together as a single class, is required to amend certain provisions of our Certificate of Incorporation.

Board Vacancies

Any vacancy on our Board of Directors may be filled by a majority vote of the directors then in office, although less than a quorum, or by a sole remaining director, subject to any special rights of the holders of preferred stock. Any director chosen to fill a vacancy will hold office until the expiration of the term of the class for which he or she was elected and until his or her successor is duly elected and qualified or until their earlier resignation, removal from office, death or incapacity. Except as otherwise provided by law, the Stockholders Agreement or our Bylaws, in the event of a vacancy in our Board of Directors, the remaining directors may exercise the powers of our full Board of Directors until the vacancy is filled.

Exclusive Forum Selection

Our Certificate of Incorporation provides that unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware will, to the fullest extent permitted by applicable law, be the sole and exclusive forum for: (i) any derivative action brought by a stockholder on our behalf, (ii) any action asserting a claim of breach of a fiduciary duty owed by any of our directors, officers or stockholders, (iii) any action arising under our Certificate of Incorporation, our Bylaws or the DGCL or (iv) any action asserting a claim against us governed by the internal affairs doctrine. Any person or entity purchasing or otherwise acquiring any interest in shares of our capital stock is deemed to have notice of and consented to the exclusive forum provisions in the Certificate of Incorporation. In addition, the Certificate of Incorporation designates the federal district courts of the United States of America as the exclusive forum for the resolution of any complaint asserting a cause of action arising under the Securities Act.

Section 27 of the Exchange Act creates exclusive federal jurisdiction over all suits brought to enforce any duty or liability created by the Exchange Act or the rules and regulations thereunder. As a result, the exclusive forum provision in the Certificate of Incorporation will not apply to suits brought to enforce any duty or liability created by the Exchange Act or any other claim for which the federal courts have exclusive jurisdiction.

Although we believe these provisions benefit us by providing increased consistency in the application of Delaware law in the types of lawsuits to which it applies, a court may determine that these provisions are unenforceable, and to the extent they are enforceable, the provisions may have the effect of discouraging lawsuits against our directors and officers, although our stockholders shall not be deemed to have waived its compliance with federal securities laws and the rules and regulations thereunder.

Section 203 of the Delaware General Corporation Law

We are subject to the provisions of Section 203 of the DGCL. In general, Section 203 prohibits a Delaware corporation that is listed on a national securities exchange or held of record by more than 2,000 stockholders from engaging in a "business combination" with an "interested stockholder" for a three-year period following the time that such stockholder becomes an interested stockholder, unless the business combination is approved in a prescribed manner. A "business combination" includes, among other things, certain mergers, asset or stock sales or other transactions resulting in a financial benefit to the interested stockholder. An "interested stockholder" is a person who, together with affiliates and associates, owns, or did own within three years prior to the determination of interested stockholder status, 15% or more of the corporation's outstanding voting stock. Under Section 203, a business combination between a corporation and an interested stockholder is prohibited unless it satisfies one of the following conditions:

15

Under certain circumstances, Section 203 of the DGCL will make it more difficult for a person who would be an "interested stockholder" to effect various business combinations with a corporation for a three-year period. This provision may encourage companies interested in acquiring us to negotiate in advance with our Board of Directors because the stockholder approval requirement would be avoided if our Board of Directors approves either the business combination or the transaction which results in the stockholder becoming an interested stockholder. Section 203 of the DGCL also may have the effect of preventing changes in our Board of Directors and may make it more difficult to accomplish transactions which stockholders may otherwise deem to be in their best interests.

Preferred Stock - Limitations on Rights of Holders of Common Stock

Our Certificate of Incorporation provides that shares of our preferred stock may be issued from time to time in one or more series. Our Board of Directors is authorized to establish the voting rights, if any, designations, preferences and relative, participating, optional or other special rights of the shares of such series, and the qualifications, limitations or restrictions thereof, applicable to the shares of each series of our preferred stock. Our Board of Directors is able to, without stockholder approval, issue our preferred stock with voting and other rights that could adversely affect the voting power and other rights of the holders of our common stock and could have anti-takeover effects. The ability of our Board of Directors to issue our preferred stock without stockholder approval could have the effect of delaying, deferring or preventing a change of control of us or the removal of existing management.

Listing of Securities

Our common stock is currently listed on the Nasdaq Global Select Market under the symbol "AEVA".

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Continental Stock Transfer & Trust Company.

Limitation on Liability and Indemnification of Directors and Officers

The Certificate of Incorporation provides that our directors and officers are indemnified and advanced expenses by the Company to the fullest extent authorized or permitted by the DGCL as it now exists or may in the future be amended. In addition, the Certificate of Incorporation provides that our directors will not be personally liable to the Company or its stockholders for monetary damages for breaches of their fiduciary duty as directors to the fullest extent permitted by the DGCL.

The Certificate of Incorporation also permits us to purchase and maintain insurance on behalf of any officer, director, employee or agent of ours for any liability arising out of his or her status as such, regardless of whether the DGCL would permit indemnification.

16

These provisions may discourage stockholders from bringing a lawsuit against our directors for breach of their fiduciary duty. These provisions also may have the effect of reducing the likelihood of derivative litigation against directors and officers, even though such an action, if successful, might otherwise benefit us and our stockholders. Furthermore, a stockholder's investment may be adversely affected to the extent we pay the costs of settlement and damage awards against directors and officers pursuant to these indemnification provisions. We believe that these provisions, the insurance and the indemnity agreements are necessary to attract and retain talented and experienced directors and officers.

Insofar as indemnification for liabilities arising under the Securities Act may be permitted to our directors, officers and controlling persons pursuant to the foregoing provisions, or otherwise, we have been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable.

17

DESCRIPTION OF DEBT SECURITIES

We have summarized below general terms and conditions of the debt securities that we may offer and sell pursuant to this prospectus. When we offer to sell a particular series of debt securities, we will describe the specific terms and conditions of the series in a prospectus supplement to this prospectus. We will also indicate in the applicable prospectus supplement whether the general terms and conditions described in this prospectus apply to the series of debt securities. The terms and conditions of the debt securities of a series may be different in one or more respects from the terms and conditions described below. If so, those differences will be described in the applicable prospectus supplement.

We will issue the debt securities in one or more series under an indenture between us and a trustee to be selected by us. The following description of provisions of the indenture does not purport to be complete and is subject to, and qualified in its entirety by reference to, the indenture, which has been filed with the SEC as an exhibit to the registration statement of which this prospectus forms a part. A form of each debt security, any future supplemental indenture or similar document also will be so filed. You should read the indenture and any supplemental indenture or similar document because they, and not this description, define your rights as holder of our debt securities. All capitalized terms have the meanings specified in the indenture.

For purposes of this section of this prospectus, references to "we," "us" and "our" are to Aeva Technologies, Inc. and not to any of its subsidiaries.

General

We may issue, from time to time, debt securities, in one or more series, that will consist of either senior debt ("Senior Debt Securities"), senior subordinated debt ("Senior Subordinated Debt Securities"), subordinated debt ("Subordinated Debt Securities") or junior subordinated debt ("Junior Subordinated Debt Securities" and, together with the Senior Subordinated Debt Securities and the Subordinated Debt Securities, the "Subordinated Securities"). Debt securities, whether senior, senior subordinated, subordinated or junior subordinated, may be issued as convertible debt securities or exchangeable debt securities.

The indenture does not limit the amount of debt securities that we may issue. We may, without the consent of the holders of the debt securities of any series, issue additional debt securities ranking equally with, and otherwise similar in all respects to, the debt securities of the series (except for any differences in the issue price and, if applicable, the initial interest accrual date and interest payment date) so that those additional debt securities will be consolidated and form a single series with the debt securities of the series previously offered and sold; provided that if the additional debt securities are not fungible with the debt securities of the series previously offered or sold for U.S. federal income tax purposes, the additional debt securities will have a separate CUSIP or other identifying number.

The indenture provides that we may issue debt securities up to the principal amount that we may authorize and may be in any currency or currency unit designated by us. Except for the limitations on consolidation, merger and sale of all or substantially all of our assets contained in the indenture, the terms of the indenture do not contain any covenants or other provisions designed to afford holders of any debt securities protection with respect to our operations, financial condition or transactions involving us.

We may issue the debt securities issued under the indenture as "discount securities," which means they may be sold at a discount below their stated principal amount. These debt securities, as well as other debt securities that are not issued at a discount, may, for U.S. federal income tax purposes, be treated as if they were issued with "original issue discount," because of interest payment and other characteristics. Special U.S. federal income tax considerations applicable to debt securities issued with original issue discount will be described in more detail in any applicable prospectus supplement.

18

Provisions of the Indenture

The applicable prospectus supplement for a series of debt securities that we issue will describe, among other things, the following terms of the offered debt securities:

The applicable prospectus supplement will set forth certain U.S. federal income tax considerations for holders of any debt securities and the securities exchange or quotation system on which any debt securities are listed or quoted, if any.

Debt securities issued by us will be structurally subordinated to all indebtedness and other liabilities of our subsidiaries, except to the extent any such subsidiary guarantees or is otherwise obligated to make payment on such debt securities.

19

Senior Debt Securities

Payment of the principal of, and premium, if any, and interest on, Senior Debt Securities will rank on a parity with all of our other unsecured and unsubordinated debt.

Senior Subordinated Debt Securities

Payment of the principal of, and premium, if any, and interest on, Senior Subordinated Debt Securities will be junior in right of payment to the prior payment in full of all of our unsubordinated debt. We will set forth in the applicable prospectus supplement relating to any Senior Subordinated Debt Securities the subordination terms of such securities as well as the aggregate amount of outstanding debt, as of the most recent practicable date, that by its terms would be senior to the Senior Subordinated Debt Securities. We will also set forth in such applicable prospectus supplement limitations, if any, on issuance of additional debt ranking senior to the Senior Subordinated Debt Securities.

Subordinated Debt Securities

Payment of the principal of, and premium, if any, and interest on, Subordinated Debt Securities will be subordinated and junior in right of payment to the prior payment in full of all of our unsubordinated and senior subordinated debt. We will set forth in the applicable prospectus supplement relating to any Subordinated Debt Securities the subordination terms of such securities as well as the aggregate amount of outstanding indebtedness, as of the most recent practicable date, that by its terms would be senior to the Subordinated Debt Securities. We will also set forth in such prospectus supplement limitations, if any, on issuance of additional debt ranking senior to the Subordinated Debt Securities.

Junior Subordinated Debt Securities

Payment of the principal of, and premium, if any, and interest on, Junior Subordinated Debt Securities will be subordinated and junior in right of payment to the prior payment in full of all of our unsubordinated, senior subordinated and subordinated debt. We will set forth in the applicable prospectus supplement relating to any Junior Subordinated Debt Securities the subordination terms of such securities as well as the aggregate amount of outstanding debt, as of the most recent practicable date, that by its terms would be senior to the Junior Subordinated Debt Securities. We will also set forth in such prospectus supplement limitations, if any, on issuance of additional debt ranking senior to the Junior Subordinated Debt Securities.

Conversion or Exchange Rights

Debt securities may be convertible into or exchangeable for other securities or property of us. The terms and conditions of conversion or exchange will be set forth in the applicable prospectus supplement. The terms will include, among others, the following:

Consolidation, Merger or Sale

We cannot consolidate or merge with or into, or transfer or lease our properties and assets substantially as an entirety to, any person, and we shall not permit any other person to consolidate with or merge into us, unless:

20

Subject to certain exceptions, when the person to whom our assets are transferred or leased has assumed our obligations under the debt securities and the indenture, we shall be discharged from all our obligations under the debt securities and the indenture.

This covenant would not apply to any recapitalization transaction, a change of control of us or a highly leveraged transaction, unless the transaction or change of control were structured to include a merger or consolidation or transfer or lease of our properties and assets substantially as an entirety.

Events of Default

Unless otherwise indicated, the term "Event of Default," when used in the indenture with respect to the debt securities of any series, means any of the following:

An Event of Default for a particular series of debt securities does not necessarily constitute an Event of Default for any other series of debt securities issued under the indenture.

If an Event of Default (other than an Event of Default relating to events of bankruptcy, insolvency or reorganization of us) involving any series of debt securities has occurred and is continuing, the trustee or the holders of a specified aggregate principal amount of the debt securities of each affected series may declare the entire principal amount of all the debt securities of such affected series, and the interest accrued thereon, if any, to be due and payable immediately. The holders of not less than a majority in aggregate principal amount of the debt securities of an affected series may, after satisfying conditions, rescind and annul any of the above-described declarations and consequences involving such series.

If an Event of Default relating to events of bankruptcy, insolvency or reorganization of us occurs and is continuing, then the entire principal amount of all of the debt securities outstanding, and the interest accrued thereon, if any, will automatically become due and payable immediately, without any declaration or other act by the trustee or any holder.

21

The indenture imposes limitations on suits brought by holders of debt securities against us with respect to an Event of Default. Except as provided below, no holder of debt securities of any series may institute any action against us under the indenture unless:

Notwithstanding the foregoing, each holder of debt securities of any series has the right, which is absolute and unconditional, to receive payment of the principal of, and premium and interest, if any, on, such debt securities when due and to institute suit for the enforcement of any such payment, and such rights may not be impaired without the consent of that holder of debt securities.

We will be required to file annually with the trustee a certificate, signed by one of our officers, stating whether or not the officer knows of any default by us in the performance, observance or fulfillment of any condition or covenant of the indenture.

Registered Global Securities

We may issue the debt securities of a series in whole or in part in the form of one or more fully registered global securities that we will deposit with a depositary or with a nominee for a depositary identified in the applicable prospectus supplement and registered in the name of such depositary or nominee. In such case, we will issue one or more registered global securities denominated in an amount equal to the aggregate principal amount of all of the debt securities of the series to be issued and represented by such registered global security or securities.

Unless and until it is exchanged in whole or in part for debt securities in definitive registered form, a registered global security may not be transferred except as a whole:

The applicable prospectus supplement relating to a series of debt securities will describe the specific terms of the depositary arrangement with respect to any portion of such series represented by a registered global security. We anticipate that the following provisions will apply to all depositary arrangements for debt securities:

22

The laws of some states may require that certain purchasers of securities take physical delivery of the securities in definitive form. These laws may limit the ability of those persons to own, transfer or pledge beneficial interests in registered global securities.

So long as the depositary for a registered global security, or its nominee, is the registered owner of the registered global security, the depositary or the nominee, as the case may be, will be considered the sole owner or holder of the debt securities represented by the registered global security for all purposes under the indenture. Except as set forth below, owners of beneficial interests in a registered global security:

Accordingly, each person owning a beneficial interest in a registered global security must rely on the procedures of the depositary for the registered global security and, if the person is not a participant, on the procedures of a participant through which the person owns its interest, to exercise any rights of a holder under the indenture.

We understand that under existing industry practices, if we request any action of holders or if an owner of a beneficial interest in a registered global security desires to give or take any action that a holder is entitled to give or take under the indenture, the depositary for the registered global security would authorize the participants holding the relevant beneficial interests to give or take the action, and those participants would authorize beneficial owners owning through those participants to give or take the action or would otherwise act upon the instructions of beneficial owners holding through them.

We will make payments of principal and premium, if any, and interest, if any, on debt securities represented by a registered global security registered in the name of a depositary or its nominee to the depositary or its nominee, as the case may be, as the registered owners of the registered global security. None of us, the trustee or any other agent of us or the trustee will be responsible or liable for any aspect of the records relating to, or payments made on account of, beneficial ownership interests in the registered global security or for maintaining, supervising or reviewing any records relating to the beneficial ownership interests.

We expect that the depositary for any debt securities represented by a registered global security, upon receipt of any payments of principal and premium, if any, and interest, if any, in respect of the registered global security, will immediately credit participants' accounts with payments in amounts proportionate to their respective beneficial interests in the registered global security as shown on the records of the depositary. We also expect that standing customer instructions and customary practices will govern payments by participants to owners of beneficial interests in the registered global security held through the participants, as is now the case with the securities held for the accounts of customers in bearer form or registered in "street name." We also expect that any of these payments will be the responsibility of the participants.

If the depositary for any debt securities represented by a registered global security is at any time unwilling or unable to continue as depositary or ceases to be a clearing agency registered under the Exchange Act, we will

23

appoint an eligible successor depositary. If we fail to appoint an eligible successor depositary within 90 days, we will issue the debt securities in definitive form in exchange for the registered global security. In addition, we may at any time and in our sole discretion decide not to have any of the debt securities of a series represented by one or more registered global securities. In such event, we will issue debt securities of that series in a definitive form in exchange for all of the registered global securities representing the debt securities. The trustee will register any debt securities issued in definitive form in exchange for a registered global security in such name or names as the depositary, based upon instructions from its participants, shall instruct the trustee.

Discharge, Defeasance and Covenant Defeasance

We can discharge or defease our obligations under the indenture as set forth below. Unless otherwise set forth in the applicable prospectus supplement, the subordination provisions applicable to any Subordinated Securities will be expressly made subject to the discharge and defeasance provisions of the indenture.

We may discharge our obligations to holders of any series of debt securities that have not already been delivered to the trustee for cancellation and that have either become due and payable or are by their terms to become due and payable within one year (or to be called for redemption within one year). We may effect a discharge by irrevocably depositing with the trustee cash or U.S. government obligations, as trust funds, in an amount certified to be sufficient to pay when due, whether at maturity, upon redemption or otherwise, the principal of, and premium, if any, and interest on, the debt securities and any mandatory sinking fund payments.

Unless otherwise provided in the applicable prospectus supplement, we may also discharge any and all of our obligations to holders of any series of debt securities at any time ("legal defeasance"). We also may be released from the obligations imposed by any covenants of any outstanding series of debt securities and provisions of the indenture, and we may omit to comply with those covenants without creating an Event of Default ("covenant defeasance"). We may effect legal defeasance and covenant defeasance only if, among other things:

Although we may discharge or defease our obligations under the indenture as described in the two preceding paragraphs, we may not avoid, among other things, our duty to register the transfer or exchange of any series of debt securities, to replace any temporary, mutilated, destroyed, lost or stolen series of debt securities or to maintain an office or agency in respect of any series of debt securities.

We may exercise our legal defeasance option notwithstanding our prior exercise of our covenant defeasance option.

Modifications of the Indenture

The indenture provides that we and the trustee may enter into supplemental indentures without the consent of the holders of debt securities to:

24

The indenture also provides that we and the trustee may, with the consent of the holders of not less than a majority in aggregate principal amount of the outstanding debt securities of all series of Senior Debt Securities or Subordinated Securities, as the case may be, then outstanding and affected thereby (voting as one class), add any provisions to, or change in any manner, eliminate or modify in any way the provisions of, the indenture or modify in any manner the rights of the holders of the debt securities. We and the trustee may not, however, without the consent of the holder of each outstanding debt security affected thereby:

25

Concerning the Trustee

The indenture provides that there may be more than one trustee under the indenture, each with respect to one or more series of debt securities. If there are different trustees for different series of debt securities, each trustee will be a trustee of a trust under the indenture separate and apart from the trust administered by any other trustee under the indenture. Except as otherwise indicated in this prospectus or any accompanying prospectus supplement, any action permitted to be taken by a trustee may be taken by such trustee only with respect to the one or more series of debt securities for which it is the trustee under the indenture. Any trustee under the indenture may resign or be removed with respect to one or more series of debt securities. All payments of principal of, and premium, if any, and interest on, and all registration, transfer, exchange, authentication and delivery (including authentication and delivery on original issuance of the debt securities) of, the debt securities of a series will be effected by the trustee with respect to such series at an office designated by the trustee.

The indenture contains limitations on the right of the trustee, should it become a creditor of us, to obtain payment of claims in some cases or to realize on certain property received in respect of any such claim as security or otherwise. The trustee may engage in other transactions. If it acquires any conflicting interest relating to any duties with respect to the debt securities, however, it must eliminate the conflict or resign as trustee.

The holders of a majority in aggregate principal amount of any series of debt securities then outstanding will have the right to direct the time, method and place of conducting any proceeding for exercising any remedy available to the trustee with respect to such series of debt securities, provided that the direction would not conflict with any rule of law or with the indenture, would not be unduly prejudicial to the rights of another holder of the debt securities, and would not involve any trustee in personal liability. The indenture provides that in case an Event of Default shall occur and be known to any trustee and not be cured, the trustee must use the same degree of care as a prudent person would use in the conduct of his or her own affairs in the exercise of the trustee's power. Subject to these provisions, the trustee will be under no obligation to exercise any of its rights or powers under the indenture at the request of any of the holders of the debt securities, unless they shall have offered to the trustee security and indemnity satisfactory to the trustee.

No Individual Liability of Incorporators, Stockholders, Officers or Directors

The indenture provides that no incorporator and no past, present or future stockholder, officer or director of us or any successor corporation in their capacity as such shall have any individual liability for any of our obligations, covenants or agreements under the debt securities or the indenture.

Governing Law

The indenture and the debt securities will be governed by, and construed in accordance with, the laws of the State of New York.

26

DESCRIPTION OF WARRANTS

General

We may issue debt warrants for the purchase of debt securities or stock warrants for the purchase of preferred stock or common stock.

The warrants will be issued under warrant agreements to be entered into between us and the purchasers or between us and a bank or trust company, as warrant agent, all to be set forth in the applicable prospectus supplement relating to any or all warrants in respect of which this prospectus is being delivered. We will file a copy of the warrant and warrant agreement with the SEC each time we issue a series of warrants, and these warrants and warrant agreements will be incorporated by reference into the registration statement of which this prospectus forms a part.

The following description sets forth certain general terms and provisions of the warrants to which any applicable prospectus supplement may relate. The particular terms of the warrants to which any applicable prospectus supplement may relate and the extent, if any, to which such general provisions may apply to the warrants so offered will be described in the applicable prospectus supplement. The following summary of certain provisions of the warrants, warrant agreements and warrant certificates does not purport to be complete and is subject to, and is qualified in its entirety by express reference to, all the provisions of the warrant agreements and warrant certificates, including the definitions therein of certain terms.

Debt Warrants

General. Reference is made to the applicable prospectus supplement for the terms of debt warrants in respect of which this prospectus is being delivered, the debt securities warrant agreement relating to such debt warrants and the debt warrant certificates representing such debt warrants, including the following:

The debt warrant certificates will be exchangeable for new debt warrant certificates of different denominations and debt warrants may be exercised at the corporate trust office of the warrant agent or any other office indicated in the applicable prospectus supplement. Prior to the exercise of their debt warrants, holders of debt warrants will not have any of the rights of holders of the debt securities purchasable upon such exercise and will not be entitled to any payments of principal and premium, if any, and interest, if any, on the debt securities purchasable upon such exercise.

27

Exercise of Debt Warrants. Each debt warrant will entitle the holder to purchase for cash such principal amount of debt securities at such exercise price as shall in each case be set forth in, or be determinable as set forth in, the applicable prospectus supplement relating to the debt warrants offered thereby. Unless otherwise specified in the applicable prospectus supplement, debt warrants may be exercised at any time up to 5:00 p.m., New York City time, on the expiration date set forth in the applicable prospectus supplement. After 5:00 p.m., New York City time, on the expiration date, unexercised debt warrants will become void.

Debt warrants may be exercised as set forth in the applicable prospectus supplement relating to the debt warrants. Upon receipt of payment and the debt warrant certificate properly completed and duly executed at the corporate trust office of the warrant agent or any other office indicated in the applicable prospectus supplement, we will, as soon as practicable, forward the debt securities purchasable upon such exercise. If less than all of the debt warrants represented by such debt warrant certificate are exercised, a new debt warrant certificate will be issued for the remaining amount of debt warrants.

Stock Warrants

General. Reference is made to the applicable prospectus supplement for the terms of stock warrants in respect of which this prospectus is being delivered, the stock warrant agreement relating to such stock warrants and the stock warrant certificates representing such stock warrants, including the following:

The stock warrant certificates will be exchangeable for new stock warrant certificates of different denominations and stock warrants may be exercised at the corporate trust office of the warrant agent or any other office indicated in the applicable prospectus supplement. Prior to the exercise of their stock warrants, holders of stock warrants will not have any of the rights of holders of shares of capital stock purchasable upon such exercise, and will not be entitled to any dividend payments on such capital stock purchasable upon such exercise.

Exercise of Stock Warrants. Each stock warrant will entitle the holder to purchase for cash such number of shares of preferred stock or common stock, as the case may be, at such exercise price as shall in each case be set forth in, or be determinable as set forth in, the applicable prospectus supplement relating to the stock warrants offered thereby. Unless otherwise specified in the applicable prospectus supplement, stock warrants may be exercised at any time up to 5:00 p.m., California time, on the expiration date set forth in the applicable prospectus supplement. After 5:00 p.m., California time, on the expiration date, unexercised stock warrants will become void.

28

Stock warrants may be exercised as set forth in the applicable prospectus supplement relating thereto. Upon receipt of payment and the stock warrant certificates properly completed and duly executed at the corporate trust office of the warrant agent or any other office indicated in the applicable prospectus supplement, we will, as soon as practicable, forward a certificate representing the number of shares of capital stock purchasable upon such exercise. If less than all of the stock warrants represented by such stock warrant certificate are exercised, a new stock warrant certificate will be issued for the remaining amount of stock warrants.

29

SELLING STOCKHOLDER

As previously disclosed, on May 13, 2025, we entered into a subscription agreement with the selling stockholder, pursuant to which we agreed to sell and issue in a private placement (the "Private Placement") an aggregate of 3,509,719 shares of common stock at a price of $9.26 per share, for aggregate gross proceeds of approximately $32.5 million. The closing of the Private Placement occurred on August 20, 2025. This prospectus covers the resale or other disposition from time to time by the selling stockholder of the resale shares that were issued to the selling stockholder by us in the Private Placement. We are registering the offer and sale of the resale shares to satisfy certain registration obligations that we granted the selling stockholder in connection with the Private Placement.

The following table sets forth certain information provided by or on behalf of the selling stockholder concerning the common stock that may be offered from time to time by such selling stockholder pursuant to this prospectus. The selling stockholder identified below may have sold, transferred, or otherwise disposed of all or a portion of their securities after the date on which they provided us with information regarding their securities. Any changed or new information given to us by the selling stockholder, including regarding the identity of, and the securities held by, such selling stockholder, will be set forth in a prospectus supplement or amendments to the registration statement of which this prospectus is a part, if and when necessary. The selling stockholder may sell all, some or none of such securities in this offering. See "Plan of Distribution."

The table is based on information supplied to us by the selling stockholder, with beneficial ownership and percentage ownership determined in accordance with the rules and regulations of the SEC. This information does not necessarily indicate beneficial ownership for any other purpose. We have based our calculation of the percentage of beneficial ownership of the selling stockholder before the offering on 62,984,603 shares of common stock outstanding as of March 31, 2026. Percentage ownership of shares of our common stock after this offering gives effect to the sale by the selling stockholder of 3,509,719 shares of our common stock in this offering. The information in this table assumes the sale of all shares offered by the selling stockholder and that the selling stockholder does not acquire any additional shares.

The registration for resale of the shares does not mean that the selling stockholder will sell or otherwise dispose of all or any of these shares of common stock. The selling stockholder may sell or otherwise dispose of all, a portion or none of such shares from time to time. We do not know the number of shares, if any, that will be offered for sale or other disposition by the selling stockholder under this prospectus. We currently have no agreements, arrangements or understandings with the selling stockholder regarding the sale of any of the shares.

30

LEGAL MATTERS

The validity of the securities being offered hereby is being passed upon for us by Gunderson Dettmer Stough Villeneuve Franklin & Hachigian, LLP, Redwood City, California. As appropriate, any underwriters will also be advised about the validity of the securities and other legal matters by their own counsel, which will be named in the applicable prospectus supplement.

EXPERTS

The consolidated financial statements incorporated in this prospectus by reference have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their report. Such financial statements are incorporated in reliance upon the report of such firm given their authority as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the Internet at the SEC's website at http://www.sec.gov. Copies of certain information filed by us with the SEC are also available on our website at https://www.aeva.com. Information accessible on or through our website is not incorporated herein or a part of this prospectus.

This prospectus is part of a registration statement we filed with the SEC. This prospectus omits some information contained in the registration statement in accordance with SEC rules and regulations. You should review the information and exhibits in the registration statement for further information on us and the securities we or the selling stockholder are offering. Statements in this prospectus concerning any document we filed as an exhibit to the registration statement or that we otherwise filed with the SEC are not intended to be comprehensive and are qualified by reference to these filings. You should review the complete document to evaluate these statements.

INCORPORATION BY REFERENCE

The SEC allows us to incorporate by reference much of the information we file with the SEC, which means that we can disclose important information to you by referring you to those publicly available documents. The information that we incorporate by reference in this prospectus is considered to be part of this prospectus. Because we are incorporating by reference future filings with the SEC to the extent set forth herein, this prospectus is continually updated and those future filings may modify or supersede some of the information included or incorporated by reference in this prospectus. This means that you must look at all of the SEC filings that we incorporate by reference to determine if any of the statements in this prospectus or in any document previously incorporated by reference have been modified or superseded. This prospectus incorporates by reference the documents listed below and any future filings that we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (in each case, other than those documents or the portions of those documents furnished (but not filed) pursuant to Items 2.02 or 7.01 of any Current Report on Form 8-K), until the offering of the common stock being registered under this prospectus is terminated or completed:

31

We will provide without charge to each person, including any beneficial owner, to whom a copy of this prospectus is delivered, upon written or oral request of any such person, a copy of any or all of the documents that have been or may be incorporated by reference into this prospectus at no cost. Any such request may be made in writing or by telephoning us at the following address or telephone number:

Aeva Technologies, Inc.

555 Ellis Street

Mountain View, CA 94043

(650) 481-7070

32

PART II. INFORMATION NOT REQUIRED IN PROSPECTUS

The following table sets forth the estimated costs and expenses, other than underwriting discounts, payable by the Registrant in connection with the offering of the securities being registered.

Section 145 of the Delaware General Corporation Law provides that a corporation has the power to indemnify a director, officer, employee or agent of the corporation and certain other persons serving at the request of the corporation in related capacities against expenses (including attorneys' fees), judgments, fines and amounts paid in settlements actually and reasonably incurred by the person in connection with an action, suit or proceeding to which he or she is or is threatened to be made a party by reason of such position, if such person acted in good faith and in a manner he or she reasonably believed to be in or not opposed to the best interests of the corporation, and, in any criminal action or proceeding, had no reasonable cause to believe his or her conduct was unlawful, except that, in the case of actions brought by or in the right of the corporation, no indemnification shall be made with respect to any claim, issue or matter as to which such person shall have been adjudged to be liable to the corporation unless and only to the extent that the Court of Chancery or other adjudicating court determines that, despite the adjudication of liability but in view of all of the circumstances of the case, such person is fairly and reasonably entitled to indemnity for such expenses which the Court of Chancery or such other court shall deem proper.

As permitted by Section 145 of the Delaware General Corporation Law, the Second Amended and Restated Certificate of Incorporation ("Certificate of Incorporation") and amended and restated bylaws of the Registrant provide that:

II-1

The Registrant's policy is to enter into agreements with its directors and executive officers that require the Registrant to indemnify them against expenses, judgments, fines, settlements and other amounts that any such person becomes legally obligated to pay (including with respect to a derivative action) in connection with any proceeding, whether actual or threatened, to which such person may be made a party to or participant in by reason of the fact that such person is or was a director, officer, employee, agent or fiduciary of the Registrant or any of its affiliates, provided such person acted in good faith and in a manner such person reasonably believed to be in, or not opposed to, the Registrant's best interests.

The Registrant also maintains a directors' and officers' liability insurance policy. The policy insures directors and officers against unindemnified losses arising from certain wrongful acts in their capacities as directors and officers and reimburses the Registrant for those losses for which the Registrant has lawfully indemnified the directors and officers. The policy contains various exclusions.

These indemnification provisions and the indemnification agreements entered into between the Registrant and its officers and directors may be sufficiently broad to permit indemnification of the Registrant's officers and directors for liabilities (including reimbursement of expenses incurred) arising under the Securities Act.

Exhibit Index

II-2

The undersigned Registrant hereby undertakes:

(1) to file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) to include any prospectus required by Section 10(a)(3) of the Securities Act of 1933, as amended (the "Securities Act");

(ii) to reflect in the prospectus any facts or events arising after the effective date of this registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in this registration statement.

Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Securities and Exchange Commission (the "SEC") pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20 percent change in the maximum aggregate offering price set forth in the "Calculation of Registration Fee" table in the effective registration statement; and

(iii) to include any material information with respect to the plan of distribution not previously disclosed in this registration statement or any material change to such information in this registration statement;

provided, however, that paragraphs (1)(i), (1)(ii) and (1)(iii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the Commission by the Registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 , as amended (the "Exchange Act") that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

II-3

(2) that, for the purpose of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof;

(3) to remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering;

(4) that, for the purpose of determining liability under the Securities Act to any purchaser:

(i) each prospectus filed by the Registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

(ii) each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5) or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii) or (x) for the purpose of providing the information required by Section 10(a) of the Securities Act shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

(5) that, for the purpose of determining liability of the Registrant under the Securities Act to any purchaser in the initial distribution of the securities, the undersigned Registrant undertakes that in a primary offering of securities of the undersigned Registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned Registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i) Any preliminary prospectus or prospectus of the undersigned Registrant relating to the offering required to be filed pursuant to Rule 424;

(ii) Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned Registrant or used or referred to by the undersigned registrant;

(iii) The portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned Registrant; and

(iv) Any other communication that is an offer in the offering made by the undersigned Registrant to the purchaser.

(6) that, for purposes of determining any liability under the Securities Act, each filing of the Registrant's annual report pursuant to Section 13(a) or 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan's annual report pursuant to Section 15(d) of the Exchange Act) that is incorporated by reference in this registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(7) Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the Registrant pursuant to the foregoing provisions, or otherwise, the

II-4

Registrant has been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or paid by a director, officer or controlling person of the Registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the Registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue; and

(8) To file an application for the purpose of determining the eligibility of the trustee to act under subsection (a) of Section 310 of the Trust Indenture Act in accordance with the rules and regulations prescribed by the SEC under Section 305(b)(2) of the Trust Indenture Act.

II-5

SIGNATURES

Pursuant to the requirements of the Securities Act, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in Mountain View, California, on June 3, 2026.

KNOW ALL PERSONS BY THESE PRESENTS, that each of the undersigned directors or officers of Aeva Technologies, Inc. a Delaware corporation (the "Company"), hereby constitutes and appoints Soroush Salehian Dardashti and Saurabh Sinha, and each of them, as his or her true and lawful attorney-in-fact, with full power of substitution and resubstitution, for him or her and in his or her name, place and stead, in any and all capacities, to execute a Registration Statement on Form S-3 of the Company, and any and all amendments (including post-effective amendments) to such Registration Statement and any Registration Statement relating to any offering made pursuant to this Registration Statement, and to file such Registration Statement(s) and any and all amendments thereto, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorney-in-fact full power and authority to do and perform each and every act and thing necessary or desirable to be done in and about the premises, as fully to all intents and purposes, as he or she might or could do in person, hereby ratifying and confirming all that said attorney-in-fact or his substitute or substitutes may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, as amended, this registration statement has been signed by the following persons in the capacities and on the dates indicated.

II-6