Does You Android drains battery after system update? I've recently received 2 updates for my Samsung Galasy S5 (SM-G900F) Android 5.0 
There was security patch 2015-05-01, and some other update.

I can not prove that, but my battery drains like 3x faster than before updates, and phone is visibly slower. It may be some stuff in my system, but for now I blame the update. 

Making it more wired: how could we check, if the producer does not 'break' it's own system (by making it slower, drain battery faster) to switch to a new phone?

Any suggestion on how to track the battery-draining/processor-heavy tasks, or a nice Cyanogen for my phone? It's still under warranty, so I'd prefer not to switch to CM yet.
I did wipe the phone to factory setup, and carefully restore selected applications.
Seems to work for now, but this is terrible update system!