Kind of late to the party on this one, but a very good topic nonetheless. I really don't know how safe these batteries are. I see on the news that these battery powered bikes in NYC, go up in flames, quite often. People store them inside and the next thing they know, their apt. is on fire. It's really scary. I have DeWalt battery powered tools and when I recharge the battery, the charger is always on the cement floor or steel table, away from flammable items and pray for the best. I try to monitor this closely, Carmine.