Well out of that crop firestorm is the only real budget drill. I've seen it happen to skills and some other budget drills. Plus the chargers that come with dewalts, makitas, and the like have protection in them to keep a bad battery from killing them. This firestorm charger is just a transformer with leads, i.e. absolutely no protection.
I hope you can get that charger for free, that would be really great! the chargers that those places sell aren't stock and should have that protection in them