I just installed 6 modifications onto the bus and upon entry into the bus, where my storage boxes are located, the 'dead battery sound' goes off. I have tried 3 different Heavy-Duty Batteries and all including the last where the light switch was off and the sound was still played and all of the batteries are at 0%, battery %'s where as follows before putting in bus, 58%, 100%, 85%. Now I have 3 dead batteries no battery charger and no bus :((