iFixit's iPad mini 4 teardown shows smaller battery, heavy similarities to iPad Air 2 - 9to5Mac
How to change the AirTag battery | AppleInsider
IPAD BATTERY REPLACEMENT
New Battery for iPad Air Battery Replacement Kit for iPad 5 Generation A1474, A1475, A1476 with Full Set Installation Tools|Tablet Batteries & Backup Power| - AliExpress