iPhone 6+ Photos "Background Activity" is using up my battery.
I have an iPhone 6+ with iOS 8.4 (the most current version) and 128GB of storage. Up until about 10 days ago I've been very pleased with the battery life. The phone used to easily make it a day and a half without a charge. Now I find that the battery can't make it through a day. The "Battery Usage" screen shows that it's Photos "Background Activity" that's using up the battery. I started being careful to not start Photos, but that didn't help. I also check from time to time (by double-hitting the home button) to make sure that Photos isn't running. It isn't. Last weekend I backed up and restored the iPhone. That didn't help. I'm out of ideas. Does anyone else have any?
iPhone 6 Plus, iOS 8.4, 128 GB memory