when u buy one
1. take out 6 screws open up backpack get a plastic sandwich container and cover the top of the battery .to stop any water getting on battery connectors as this will rust the connectors and they WILL snap off .
2. when u screw it back on seal the joint with sealent .
3.with the controller undo small nut holding it on and push sealent into the gap n screw it back on .
if like some of u said your wcw back packs have stopped working it could be
1.the connectors on battery have rusted n snapped off or
2. the controller has packed in due to water getting into gap .wcw says they can be dried out .but i disconnected mine n worked it off a tap .untill they sent me a controller for free .i had to buy a new battery .
iv since took the above precautions to prevent this happening again
hope these tips are some use . tacky