How to find out which apps are draining the battery? I'm not sure when it started, but my phone is draining its battery even when being charged. It's likely to be caused by some apps I installed recently. How to find out which apps are causing the problem? Is the builtin Settings -&gt; Battery statistics accurate enough?
I think the "Battery" in "Settings" might give a hint and you should turn off  those apps working in the background when you don't use them. 

And play your phone in somewhere cool, because hot atmosphere will also drain the battery fast.

Also you can download a third party app like GSam Battery Monitor(https://play.google.com/store/apps/details?id=com.gsamlabs.bbm) to check out what makes your battery drain so fast.