My phone/device is a Samsung Galaxy S Duos 2, I have been experiencing this problem since January, at times, when it's just on my pocket, it would vibrate, so I'll take it out to check just to find out that it had shut down, when I turned it on, it was at 2%, I'm 100% sure I fully charged it, this happened more than so many times. When it drains to 0, sometimes, without my charger, I will have to wait until I get home, but once I get home and charge it, I see that it still has like 50% more battery. There are also times when I'm just using it for facebook/text messaging when the screen buttons (the ones beside the home button) would suddenly go crazy like being pressed when I already put it down, and then I would notice the battery charge ticking away, it can drain like 100% in just mere seconds that I have to rush to get my charger, once I plug the charger, everything would go back to normal. It would even sometimes drain at night at 100% waking up to a seriously drained cellphone. My room is air conditioned by the way, if that helps suggestions. I checked my battery and found out that it had a small bulge on it, so I went ahead and bought me a new battery. I thought it was all over, having a new battery, but it still keeps happening. I had to install Battery Doctor and CM Clean to try to fix the problem, but still, nothing works, I even set the "Do not keep activities" in Developer Options to make sure nothing else is running except the app I'm using, but it still persists, it keeps draining, and when it drains, it messes up my screen buttons. Suggestions? Comments? Help!? Sorry, I cant show any screenshots, I'd try but it won't take screenshots when draining.