I had a no name 808 battery go on and then not go off again when I started vaping it. I couldn't get it to turn off, it just stayed on. So, I put it in a metal tub outside to let it drain itself and then I got rid of it. It wasn't on a charger, for which I'm thankful. After researching here and a few other places - and not just about ecigs - I will not leave a charging battery unattended or overnight on the charger. That includes my ecigs, my cameras' batteries, and my cell phone. Batteries can overheat on occasion; and eventually all of them will just go dead. It's what batteries do. I'm just taking precautions with all my rechargeable batteries to make sure I charge and use them properly.