LG G2 powers off repeatedly when in use

[TheKing171]

My LG G2 has been with me for about a year and now the phone is starting to annoy me really quickly. My phone only works for a few minutes after turning on until it just randomly freezes and then shuts down as if there's no more battery life even though there is. I literally have to turn my phone on like 20 times so I can get anything done. it does this even if It's charging, literally connected to the cable.