My phone keeps rebooting with wierd lines across screen

I think it's something to do with the battery...when the battery is low, my phone gets these weird lines across the screen which are horizontal, they look like the lines you get on your computer monitor when someone calls you when your mobile phone is close to the monitor.

Today my battery was 43% and I got those woerd lines across my screen and then the phone rebooted, I restarted my phone and the battery was 1%, can anyone help? Btw...I am using stunner version 2.4.27, thanks.