I've had trouble twice now, with V-mounts that don't quite fit snugly into light controllers, and when they move around they create a short that ruin the battery, and in this most recent case, the controller:
https://www.tendrile.com/2020/8/5/pzwfzl077owncvntqsdlqo51k61vey
This $150 battery is now toast. The mangled lead you see actually melted enough to pull the sleeve away from the controller with it.
My question is "How have others dealt with this issue?" The best I can come up with is to gaffe-tape the hell out of it so it doesn't move around.