"This accessory may not be supported" - iPhone 6

Hi - hoping someone can help me here.

I'm using the charger that came with my iPhone 6 - it charges fine, but whenever it gets to around 100% (sometimes around 95%) I get the error message "This accessory may not be supported" and it the lighting bolt over the battery turns off.

I tried using the phone for 10-15 minutes online while plugged in and even though the charge icon wasn't over the battery, it didn't drop any percentage, but I've gotten this message after every charge.

If I unplug, and re-plug back in, it comes back over after a few minutes if the battery level is between 95-100.

I tried using my wife's iPhone 5C charge block and got the same message.

Anyone else?

I contacted apple support, and the senior adviser recommended doing a full restore from iTunes as apparently, a restore from the phone itself won't re-install the operating system.

I just finished that this morning, so now that the battery is down to 95%, i'm charging it as we speak to see if the problem has been corrected. She said if it's not, let her know and they will arrange a full replacement device.