battery wont fully charge

It is possible your battery is dying. Batteries have a finite number of charge/discharge cycles.

You can get it replaced, that said if your device is really an ipad 2 your money will better be spent towards a new device instead of the ipad 2. THat device is about 10 years old and teetering on the edge of being obsolete.

Gotcha. In that case, and especially if your device is still under warranty, make an appointment and get it checked out