Default Galaxy Tab 2, Charging problem.

Hi friends,

I've been using my tab for over a year now, but since the last few days I am having issues with charging, the tab shows 0% and when I keep it on charging within a minute the battery shows 100% and then keeps decreasing, even after keeping it for charge the entire night the battery just doesn't charge, even last night it was charging but today when I woke up the battery was only 37%.

I searched online, tried a few solutions that i found, resetting the battery, tried flashing back to some older ROM, din't work. So guys please tell me is this a battery issue which would be solved by changing the battery only or is there any other solution?

Thanks