I picked up my Revo used. It had a pair of 3s lipos with it, but the balance plugs had broken wires. My charger didn't want anything to do with them. I bought a pair of new 2s and have been running them (plenty of power). But I got brave and opened the 3s's up today. After getting in there, I stripped the little wires and soldered them back onto the batt terminals. Pretty simple but it was a lil nerve racking at 1st. I charged them up and they work great again.