Showing as charging when not please read comments

Are you using a Bluetooth keyboard or a wired one? Can you provide a link to the keyboard in question?

I ask because wired accessories can cause issues with the charging circuit of iDevices. An MFi-certified accessory should be fine but even then, you never really know until its too late ;>).

When troubleshooting charging issues, I would do the following (in order):

1. Always try another Lightning cable and charger, preferably Apple original or MFi certified units. Make sure you are using the proper charging brick, in this case the 12W charger.
2. The Lightning cable 8-pin connector should be sitting flush with the housing and completely inserted. If it is not, there could be lint/dust/debris inside the port impeding a proper connection. You can clean it out with fine point toothpick. Just be careful not to damage the pins inside the Lightning Port.
3. Change the battery. The battery is the weakest link in the entire device and certainly for charger related issues. However, replacing the battery is not a trivial undertaking. Instead, use a battery utility, such as coconutBattery (for Mac) or 3uTools (for Windows) to test the battery prior to removal. Anything less than 70% of design capacity will require replacement.
4. If the battery is in good condition, you can use a USB Ammeter to determine if the phone is really drawing current when it says it's charging.
5. If a new battery and charge port still don't resolve the issue, then you may have a logic board issue. There is an IC (commonly referred to as Tristar) responsible for communicating with the charging device and uncertified chargers can damage it.