6s battery - I'm confused

[cbelt3]

"Low Power Mode" ? I have to keep my 6s in that mode or it sucks itself dry in less than 2 hours. And mine claims to be at 91%. And I had Apple replace the battery last year when they had that $25 price going.

I will say that 'performance management protections' make the phone almost unusable, so I turn it off all the time.