It just started again, this time on the m10. Strange. I wonder if Google has a programming glitch?
Google Play Services is most of the phone. If you're doing a lot with it, or your mobile signal is weak, or a few other things, Google Play Services will use a lot of battery temporarily.
A corrupt battery file can cause the phone to keep reading the same file over and over (it gets almost to the end, then is pointed back to the beginning), and that eats a LOT of battery. Which is why media is only scanned when the phone is restarted and if you run a rescan app - scanning every time you play a song or look at a pic would kill the battery in about an hour. It shows as Google Play services sometimes, but it's really Media Scan that's causing the drain.
I used to have similar issues, where Google Play Services drains my battery, I then followed someone's advice to go to Settings > Applications > look for Google Play Services > Manage Storage > Clear All Data. It worked flawlessly for me and didn't affect anything else. Battery stopped draining. You may want to try at your own risks as I do not know what side effect it might cause to your phone. Good luck.