I have the HP Prime G2 purchased in November of 2020. Its rechargeable battery stopped holding a charge. Oddly enough, HP does not currently offer a replacement, but I found one that is a perfect fit both physically and for specs. It is the Samsung EB-L1G6LLU Lithium Ion origianlly for the Samsung G3 phone. I got mine at Amazon for about $12. I don't know if it will work on earlier Prime models, but it works perfectly in the G2 Prime.
TheLastMillennial says the Samsung I mentioned works on all Prime models, and I believe him. I know from personal experience that it works perfectly on the G2 version.
