Default strange battery issue. drains completely and goes back to normal even w other roms

Hi I'm having a really weird issues with my e970. It runs fines and I've checked the battery status with the *#*# code which says health is good. I've tried two different roms and I end up with the issue. My phone charges fine then will I'm using it it completely turns off. No warnings or anything. I plug it in and it says zero percent. I checked it a minute later and it goes up to 20 percent. Even on twrp or from the charging screen I get random percentages. Is it the battery or something else?