I was noticing a real drain on my iPhone 6 Plus battery after pairing my Apple Watch. My iPhone used to make it two days between charges, but after the Watch I was looking at barely a day!
Turns out the main culprit is the Apple Watch Companion app that runs on the phone. That app can be quit and the Watch will continue to function as normal. And, suddenly, much less battery usage. Clearly, Apple has some programming to do!
So, if you are seeing a drain on your iPhone battery, try quitting that Companion App.
Back to playing!
p.s. The Watch battery is holding up great. It’s at 57% at 6pm and I attached it to my wrist at about 7am. Much better than I expected.
Update: Started at 100% on both devices at 7am. At 2:45 pm, Watch is at 74% and iPhone Plus is at 61%. I was using the iPhone Plus camera for a bit which used some battery. But, this is more battery use than normal for me, so it looks like there is still some drain on the iPhone Plus while it is connected to the Watch. Basically, I’ll have to go back to charging the iPhone Plus every night if/until this changes.
This is interesting because everyone was concerned about the Watch battery life; no one was talking about what it would do with the iPhone battery. Turns out we may have been looking in the wrong place. All that said we are at 1.0 here and I am sure things will develop rapidly.
Really gotten into using the watch and iPhone to track my activity. It works really, really well, and there is a ton of data collected. Looking forward to adding more health related apps.