8 x AA battery holder : ID 449 : $2.95 : Adafruit Industries, Unique & fun DIY electronics and kits
4 x AA Battery Holder with Premium Jumper Header Wires : ID 3859 : $2.95 : Adafruit Industries, Unique & fun DIY electronics and kits
5 x AA 7.5V Power Battery Storage Case Plastic Battery Box 5 AA Battery Holder Battery Case With Cable Series 5 Slots DIY|Replacement Parts & Accessories| - AliExpress
5 Slots AA Battery Box Battery Holder Board for 5 x AA Batteries DIY kit Case|Integrated Circuits| - AliExpress