I spent 2 weeks dealing with severe battery problems on my Nexus 7. After trying every "trick" I learned from this forum to no avail, I called Google to return it. I got a new one within 2 days but had 21 days to return the defective unit. So I thought I'd try using the new charger on my old device. Voila! It charged right up and now works fine. So after a few days of having no tablet at all due to my inability to get the original N7 to work, I now have 2 devices to play with (for a couple of weeks anyway). The moral: Don't assume it's the battery. It could be the charger. However, if you don't have another charger to use (as I didn't), I don't know what help knowing this will be.