Samsung S6 keeps crashing and killing batter.

[Android Central Question]

I have a Samsung S6. A few months ago it started playing up and kept crashing and showing a lot less amount of battery after the crash than prior. Example: it might be on 90%, crashes/resets, comes up with 47%, does it again then shows 1%.
I bought a new battery in case it was a battery issue, and it was okay for about a week and then began doing the same thing. I have reset it to factory settings and it still has the same problem even with the new battery. It only stays on if tethered to a charging cable at all times. As soon as it is off charging it does its crash routine again.

 

[belodion]

That may need repairer diagnosis. The battery may be bad, or something in the phone is damaging it, or there is some other fault.