Hello there,
two weeks ago I got new MacBook Retina 13 and the first thing was upgrading to MacOS Sierra.
The problem was that battery life was quite problematic, as you will see, one of the causes could be Sierra and Photo Mechanic:
1) either the battery went down really quick
2) the battery was losing it's capacity even when the comp was in sleep in backpack - once it lost cca. 70% of capacity in 2 hours and it was burning hot, the Activity Monitor said, under Energy, Preventing Sleep - PhotoMechanic - Yes.
After this, I downgraded back to El Capitan and everything works perfectly. Does anyone else have this problems on Sierra? Or should I wait a bit still to upgrade to Sierra?