Battery holder: 1 x AA Battery Holder With 6" 26AWG Wire Leads - RoHS Compliance (BCAA)
AA Battery Holder – Rocket Scream
3 x AA Battery Holder with On/Off Switch, JST, and Belt Clip - Pimoroni
8 x 1.5V AA 12V Battery Storage Holder 8AA Battery Case AA Battery Box Battery Clip Slot Double Layer Back To Back With Cable|Battery Storage Boxes| - AliExpress
ABC01 Battery clip set for four AA batteries - Box Enclosures: