Bigbadjohn

I was going up a hill with headwind looks like BMS is fried, What are those black spots on the zinc connectors does not look good, what would cause that 48V 350 watt front wheel motor.
Battery was kept in a bag so no cooling.
What type of new BMS would I need for 48V not sure how many batteries.

Thanks






batteries are OK measure 49V

Doc_Wui

Is that a toaster or a battery? The wires melted the solder and came off. You got burn marks on the cloth sheathing?. You got burn marks on the balance wires under the wrapping? Unless that last picture is a shoe, the battery case even melted.

I think this battery ought to be. and I quote from one of the other guys here, "put in a place where you wouldn't mind a fire." You might be crazy to try and salvage it.

2old

+1^^^^^^^ The BMS didn't protect the battery which must have been poorly constructed. Which bike was this to caution others?

Bigbadjohn

I bought battery used don't know brand it's a self built bike, looks like Samsung batteries Why does it have burn marks on the zinc connectors is it because of the overload and BMS failure.

Doc_Wui

If you mean these, your wires probably got hot, burned thru the wax paper and short circuited again. Or it was done by the previous user.

A BMS will isolate the battery from the outside world, i.e, disconnect it from your charger or your ebike controller. It can't help you if the cells are short circuited to each other.