The information in this preliminary prospectus supplement is not complete and may be changed. This preliminary prospectussupplement and the accompanying prospectus are part of an effective registration statement filed with the Securities andExchange Commission under the Securities Act of 1933, as amended. This preliminary prospectus supplement and the PRELIMINARY PROSPECTUS DATED MAY 8, 2025 SharesCommon Stock Twin Vee PowerCats Co. We are offering shares of our common stock in this offeringpursuant to this prospectus supplement and the accompanying prospectus. Our common stock is listed on the Nasdaq Capital Market under the symbol “VEEE.” On May 8, 2025, the last reported sale price ofour common stock on the Nasdaq Capital Market was $7.45 per share. We are an “emerging growth company” as that term is used in the Jumpstart Our Business Startups Act of 2012 and a “smallerreporting company.” As such, we have elected to comply with certain reduced public company reporting requirements. Please see Investing in our common stock involves a high degree of risk. Before making an investment decision, please read theinformation under the heading “Risk Factors” beginning on pageS-5of this prospectus supplement and in the documents Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of thesesecurities or passed upon the adequacy or accuracy of this prospectus supplement or the accompanying base prospectus. Any As of the date of this prospectus supplement, the aggregate market value of our common stock held by non-affiliates pursuant toGeneral Instruction I.B.6 of Form S-3 is $9,096,409, which is calculated based on 1,220,995 shares of our common stock outstandingheld by non-affiliates and a price of $7.45 per share, the closing price of our common stock on May 8, 2025, which is the highestclosing sale price of our common stock on the Nasdaq Capital Market within the prior 60 days of this prospectus supplement. During (1)We have agreed to reimburse the representative of the underwriters for certain expenses. Underwriting discounts andcommissions do not include a non-accountable expense allowance equal to 1.0% of the public offering price payable to theunderwriters. Please see “Underwriting” for a description of compensation payable to the underwriters. We have granted a 45-day option to the representative of the underwriters to purchase up to additional shares of common stock solelyto cover over-allotments, if any. The underwriters expect to deliver the shares of common stock to the purchasers on or about , 2025. ThinkEquity The date of this prospectus supplement is , 2025 TABLE OF CONTENTS PROSPECTUSSUPPLEMENT About this Prospectus SupplementForward-Looking StatementsProspectus Supplement SummaryThe OfferingRisk FactorsUse of ProceedsCapitalizationDividend PolicyDilutionUnderwritingLegal MattersExpertsWhere You Can Find More InformationIncorporation of Certain Information by Reference PROSPECTUS ABOUT THIS PROSPECTUS SUPPLEMENT This prospectus supplement is part of a registration statement that we have filed with the Securities and Exchange Commission (the“SEC”) utilizing a “shelf” registration process. Under the shelf registration process, we may offer shares of our common stock havingan aggregate offering price of up to $100,000,000 under the accompanying base prospectus. This prospectus supplement may add to, We provide information to you about this offering of shares of our common stock in two separate documents that are bound together:(1)this prospectus supplement, which describes the specific details regarding this offering; and (2)the accompanying base prospectus,which provides general information, some of which may not apply to this offering. Generally, when we refer to this “prospectus,” we If information in this prospectus supplement is inconsistent with the accompanying base prospectus or with any documentincorporated by reference that was filed with the SEC before the date of this prospectus supplement, you should rely on this prospectussupplement. Any statement so modified will be deemed to constitute a part of this prospectus only as so modified, and any statementso superseded will be deemed not to constitute a part of this prospectus. However, if any statement in one of these documents is This prospectus supplement, the accompanying base prospectus and the documents incorporated into each by reference includeimportant information about us, the securities being offered and other information you should know before investing in our securities.You should also read and consider information in the documents we have referred you to in the section of this prospectus supplement You should rely only on the information contained in or incorporated by reference into this prospectus supplement and theaccompanying base prospectus and any free writing prospectus we may provide to you in connection with this offering and theinformation