I founs out today if you lost the back part of your Xbox 360 controller, you can just stick two pennies on top of the batteries. I tried it a few hours
Xbox 360 Lower Case Replacement - iFixit Repair Guide
Kinect Star Wars Xbox 360 bundle review and unboxing
Side and Rear View of the Used XBOX 360 Slim Corona 250GB Console Editorial Stock Image - Image of rear, gamepad: 213836199