iPad 4 Charges Very Slowly After I updated to iOS 8.4, My iPad has been charging Very slowly.

Times:

12:00PM (noon) - iPad died, switched on charger. (1%)

1:30PM - iPad comes on. (2%)

3:00PM - 4%

4.00PM - 9%

5:10PM - 9%

What is wrong here? This is completely not normal. I have also got an iPad mini with the same charger. And charges much faster.

Charger:

10W Offical Apple Charger
Sounds like a bad battery, to me. Over time, batteries just wear out to the point of not holding a charge or charging very slowly. An iPad is pretty tough to repair, so unless you have some experience in repairing them, I'd seek a pro to replace the battery for you.