Hello,
I'm also seeing excessive battery drain on my Galaxy S4, although the battery usage graph shows that Android OS is using a lot more than Google Play. Same deal though, used to average 16-18 hours on a full charge, but my phone is almost dead after 14 hours since the update.
You can see my post about this here:
Android OS using so much Battery is the defect identified. The fix for it is to obtain a different Google Play Services apk and load it to your phone so the one with the defect is not what you are running.
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