Why does my S4 randomly power off?

[AC Question]

S4 Randomly Powers Off

Hi,

First time on here,

Basically the problem I have is since the latest update has come out (a month or so ago) my phone has randomly been switching off when it goes below (50%) for example - today at 43% the other day at 23%.

But I cant remember the last time it has fully been drained below 7%.

When it does switch off - I hold the power button to initiate the whole boot process but it just goes through the whole boot loop one after the other and the other...it doesnt stop the boot process and fully start up.

When I do put it back on charge it charges from where I last saw it have battery ie 43%. And runs perfectly normal.

I have android version 5.0.1

Thanks in advance

Amir