High Quality Acer Extensa 4620Z Replacement Battery | Laptop Battery Direct
This is an old Acer Aspire 2920. I found it for a fiver on facebook marketplace as 'not working'. I was able to get it working again by replacing the dead hard
BattPit: Laptop Battery Replacement for Acer Aspire One 521 Panthera, AK.006BT.046, BT.00607.103, LC.BTP00.087, UM09E36, UM09E75 Laptop Batteries / AC Adapters - Newegg.com