https://www.amazon.com/gp/aw/d/B01MQFT3SP/ref=mp_s_a_1_1?ie=UTF8&qid=1499966359&sr=8-1&pi=AC_SX236_SY340_FMwebp_QL65&keywords=lgv20+zerolemon&dpPl=1&dpID=51IkC7N0jgL&ref=plSrch
I use https://www.amazon.com/Battery-ZeroLemon-10000mAh-Extended-Protection/dp/B01MQFT3SP
It last about 10hrs SOT, 2.5 days average use.
I can't find a warranty website for Perfine. I think I got their smaller battery.