I figured out what was totally fscked my phone. Making contacts unusable, the CPU was ticking over all the time stealing battery.
I’d ticked “Sync Viber with Contacts” or some bullshit. Unticked that, lo and behold, battery life is awesome. I can get up at 6am and go to bed at 9pm with still 30%.
It used to die around 6pm before, flat. Now it still has 40%
Fuck you, Viber!