Well folks were asking on Facebook (it does seem like most of my “clicks” are landing there and on Yelp these days) about battery life with the new MacBook Pro 2016, I put a battery meter on this for the last few days and here’s what I’ve found even after applying the 10.12.3 update which fixed a bug that Consumer Reports had with icon caching.
TL;dr
Safari appears to be chewing up power when it is running a long time. You can check with your battery health application and restart it. Feels like either a bug or some of the web pages are running lots of JavaScript.
The details
- This application Battery Health is free and lives in the tool bar and is way more helpful than Activity Monitor for monitoring usage. When you see a spike (that is usage beyond say 5 watts), check your Activity Monitor and sort energy usage to see what is running.
- The big battery hog for me appears to be Safari. I think there is probably a bug somewhere, but normally running just a browser, I’m burning 4 watts. To see what that means, the battery in the MacBook Pro is 6700 mAH and 5 watts is about 300-500 mAH draw, so the battery should last 12 hours at that low rate.
- However, sometimes, when Safari alone is running, it pops to 14 watts, that is about 1200 mAH and that is what is getting me to 4-5 hours of life. The solution is to restart Safari and then the usage falls again.
- I also see that Spotlight also will run in the background as will the iMessage, iPhone Agent and other daemons, this causes a spike as well to 8-10 watts (600mAH-800mAH) and particularly for iMessage this can go on for a long time.
- Finally, if you do some things like Photo sharing, then you force the Mac to transcode. This gets very warm particularly for video and I see usage spike to 30-50 watts as the discrete GPU turns on.
