A fire that damaged a Stockton Springs electric and hybrid car business Sunday afternoon most likely started when a lithium battery was left in a cordless tool charger and overheated, according to the owner and fire officials. Tom Gozce, the owner of American Solartechnics Cars on Route 1, said that the tool charger was adjacent to 200 cans of spray paint in his shop, which he uses to do work on Toyota Priuses and other vehicles. “You could hear them popping,” he said.