Why is my phone turning off at 30%?

[AC Question]

I have a Galaxy S4 and my phone always turns off at about 30%, I noticed that the battery has became bigger and I replaced it, But the problem is still there, What might the problem be? Thanks in advance.

 

[anon8380037]

Hello. If the old battery was bulging it was definitely going and you needed to replace it.
Try recalibrating the new? battery by running it down from 100% without top ups three or four times. The percentage display 'might' change. Gsam is a very good monitoring app.
Otherwise it's probably a software fault on the phone, afaik, as it decides what rate and how the battery is charged during the cycle.