HPJ [Highpower International] 424B3: Registration No. 333-217294 Prospectus Supplement, Dated April 9,
[Registration No. 333-217294 Prospectus Supplement, Dated April 9, 2018 (To Prospectus dated April 20, 2017) Highpower International, Inc. Common Stock Preferred Stock Debt Securities Units This prospectus supplement amends the existing base prospectus that forms a part of the Registration Statement ]