Photos Background activity killing my battery more than 88 %

I've had this issue for several months. I have an iPhone 11 Pro Max with iOS 13.1.3. In the last 10 days, the Photos app is being reported to have used 84% of all battery usage (showing as 75 hours and 33 minutes) IN THE BACKGROUND, with only 71 minutes actually on screen...***?!

You're right, the Photos app doesn't show in the Background App Refresh list so that advice is wrong. Also, the Photos app still shows as using battery in the background when I don't even have it running in the background...in fact, it still shows when I have no apps at all running in the background.

Other than reset my device or upgrade to the latest iOS (neither of which I want to do), I've tried every suggestion I could find on every forum I could find. It seems that many people have this issue but nobody has actually found a solution.

The question you need to answer is 88% of what.

That display just tells you that photos is using most 88% of the power that is being used, not necessarily that it has consumed 88% of the battery capacity. If there were no other apps consuming power then it would show 100% even if it had only taken a tiny amount of power.

Charge your battery to 100%, wait until it is nearly empty, and then see what the percentages are.

You can also (if you wish) prevent photos from operating in the background. Settings>general>background app refresh.

I wish I could offer some actual advice, but I'm in the same situation. I've just updated to iOS 14.3 and it's still happening. In the last 24hrs, the Photos app is showing as having had 2m on screen and 13hrs 20minutes in the background! It's ridiculous and is killing my battery. I used to be able to go at least an entire day without going near a charger but I'm now having to charge it twice (sometimes 3 times) per day.

It looks like I also might have resolved this. I disabled the iCloud Photo Stream a few hours ago and so far, the Photos app hasn’t been showing in the battery usage list *and* my battery level is still 83%, 6hrs after I finished charging it.

Possibly a coincidence, but my iPad Mini started mysteriously running out of battery and I had to put it in Airplane Mode to prevent that from happening. It’s on iOS 11 so I can’t see a battery usage list. I also started seeing duplicate photos on my iPhone for no apparent reason. I’m suspecting some kind of issue with both the iPad and iPhone trying to update the iCloud Photo Stream and each one causing problems for the other. I plan to update the iPad tomorrow to iOS 14 and see what happens.

Sorry, I don't understand...you activated iCloud phone backup?

Wow...and that fixed it? I've never used iCloud for phone backups, I use iTunes instead. How long have you waited to determine if this resolved it, just out of interest...?