LETTER TO SHAREHOLDERS Q4 and Full Year 2023 March 2023 Exhibit 99.1 Letter to Shareholders March 2024 - 1 - Amprius has been in commercial battery production since 2018, and it is our belief that there are no other commercial batteries on the market that can perform at these levels today. Amprius’ high-performance battery families, SiMaxxTM and SiCoreTM, have attracted significant market attention and customer demand. The company’s priority today is to build additional manufacturing capacity as quickly as ...