I definitely agree with tA71anna as far as using battery safety when charging, especially with the Ego batteries. Actually, in studying about this subject, the smaller the battery, the less safe they are. I don't mean to make people paranoid, but it's a fact. And I know of 2 people locally that have had their Ego batteries explode while charging them. Never leave them charging while you sleep or are not at home. if they feel hot while charging them, unplug them and don't charge them again, throw them out. I had a link about this topic and battery safety but I'm not sure where it is at the moment. There are ratings for safety on batteries and the Ego/Kgo type batteries rate quite low on the list. I'm not saying they aren't safe, but they aren't the safest. There are safety features in the Ego's in case it happens and you are using them. I'm not sure how else to put it. You get what you pay for. I use AW IMR removable batteries in all my mods.