all charged up, ready to go . i was alright for about an hour then i put backpack in car to move on, i smelt a burning smell , wound my window down to see if its from outside, no so carried onto next area, set up backpack and pole to start, i smelt the same smell, out the corner of my eye i could see small puffs of smoke escaping out of the base of the backpack. . i turned it off straight away , took it home for inspection. speed controller is all gooey, i can lift it out to see a brown burnt mark on the bottom. i think this is the 3rd or 4th speed controller i have had for this backpack from WCW since i purchased it. as soon as i lifted top off the smell of burning hit you.. i advise everyone never to leave any backpack on charge overnite, i never have and never will. i cannot understand why smoke started to come from my backpack. i ve had to change the conexions again. i hope a new speed controller will get it going good again. it starts up, water comes out but you can smell burning. its only over a year old. i will let WCW know of this see what they recomend.