iPhone Battery & Blue Screen Reboot

So yesterday I put my phone on to charge left it for a couple of hours and unplugged it at 100%

I went home and a few hours later after a lot of use with my phone I noticed my iPhone was still displaying 100% battery which I knew couldn't be correct. So I switched my phone on and off again. The battery percentage corrected itself to 52% and then a couple of minutes later went to a blue screen and then the apple logo restarting the phone. It continuously did this every couple of minutes. I switched it off overnight and this morning it had gone back to 100% battery and wasn't restarting with the blue screen. As soon as I tried to find out what the correct battery was it went back into the blue screen restart loop again!

Ive tried soft and hard resets via my iTunes on my mac book pro not sure what else to do! Help please...