3S Battery Mod for Wall-e

This is a remix of the back cover for the Wall-E replica. Since there was plenty of unused space inside the original back cover, I modified it to accommodate a 3S 18650 battery holder, a 3S BMS, and a DC barrel jack for convenient charging.

The design allows everything to fit neatly inside the body, reducing external wiring and making the battery pack easy to charge without opening the robot.