I went to charge my first set of batteries - was practicing with my 2S lipos charging in series as I would with my larger 5S sets. I was sure I hooked everything up right, the charger went through it's paces and let me start charging. Within a few seconds the charger was smoking from inside.

I stopped everything. Charger appears to be working OK, but the batteries differ quite a bit in internal resistance, although I never checked them before the charge. Sometimes both batteries will tell me there is a voltage problem at the balance port.

Here are pics of the setup. The charger is capable of up to 6S charging/balancing (this was only 4). The batteries appear to be properly connected to the balancer as my other charger was able to read all the cells as one 4S battery. I hooked one red battery lead up to the other black lead, then plugged the free ends into the corresponding colors on the charger.

Not sure what I did wrong but I'm afraid to do this with my 10S setup.