Yesterday my battery on my phone went all empty. That’s unheard of and rather odd. Turns out that Google Play Services, which usually uses only a small amount of power, used an enormous amount of power. The projected time for the full battery to last was 4h. The phone was slightly warm too. Odd. A reboot did not help.
This post has a working fix: clear Play Services Data. Adding a reboot for good measure, since then battery drain is back to normal.
Update: Happened again. Turned off Backup. Since then the battery sucking problem is gone. Of course now I have no backup…