My Samsung Tab P2 3100 shows 100% battery charge in 5 minutes once i plug it in even if the charge is less than 5%. Once its unplugged the charge will be gone in no time. What can be the issue?
It apparently seems like your tablet battery has been expired or become weak. Usually it happens by over charging and leaving your tablet on charge for long even if its fully charged. Because this thing can even damage the battery of new device regardless how new it is. So in my opinion you can take it to some hardware shop to get your battery replaced or either they will suggest your first that which step to follow for reconfirming battery problem. Good Luck.
How long have you had the tablet? Is it within a warranty period? Sounds like a dud battery to me, and I'd be calling in my warranty. If you're in the EU, you get 2 years for things like this.
Conversely, if you're handy with a torx screwdriver you might want to consider buying a replacement battery and replacing it yourself.
This behavior sounds like either a dead battery or some corruption of the firmware.
I would start with resetting it to factory defaults to make sure no internal power management issue is causing it to show full charge without actually charging.
You might need to re-calibrate your battery. Search it on Google. There are plenty of guides available.
I agree, this works for Laptops and Mobile Devices, I did this with a phone I had and it worked well.
I believe it has to do with full charge discharge cycles, however there is definitely more to it.
Fix power consumption problems and extend the laptop battery life