iPhone 8 battery drain

[Peck]

Hi all - hoping for a bit of advice. The wife’s iPhone 8 has suddenly started losing charge massively and very quickly. The battery health is mid 80s (so obviously not great) but this just makes no sense. It can go from 100 to 0% in 30 minutes flat. She’s turned off all background apps etc and it’s still happening. It seems to happen when she’s online rather than actually calling someone (when it seems fine)

There are some suggestions online that one of the recent updates has caused this. I know this sort of thing has happened in the past so my questions for the experts is 1) is this problem likely to be an update issue and 2) how long does it usually take for apple to resolve?

Thank you for any advice!

[Tokyo Tokei]

My iphone7 did this after updating (admittedly, also an old phone on the original battery) to 14.something, but the latest release was fine.

When it was bad, a full switch off (hold the power button down) and reboot fixed it. Worth a try. Some games or apps seem to continuously send "analytics" (aka tracking) in the background and it can be worth "swiping up" on these to close them when not in use. Scrabble is bad for this, and Facebook of course. The full switch off and reboot should clear all these, at least until you fire them up again. Make sure all the apps are also updated post the iOS update - they may be using older, less optimised APIs if not.

If this doesn't help, try switching to Airplane mode or switching off Background App Refresh and see if the battery usage stabilises. If it does, it is some errant app either trying to update itself (or track) and burning through cpu. Turn on App Refresh for just the apps you use, one by one, and see if it is better.

[JeremyO]

I had a similar problem with my iPhone SE, original model. Battery health was showing at 94%.

I found that switching it off and on again usually restored battery strength. I eventually spoke to Apple who did a diagnostics on the phone and then restored to factory settings. This seemed to do the trick.

[smalleyboy1]

Replaced my sons iPhone 7 yesterday with a new SE as he has had the same problem for the last few months. His phone was 2.5 years old. I used to have 8 and it also suffered. Not sure if it is the updates or just the battery gets knackered with time and charging.

I believe Apple do a battery replacement for circa £90 which might be worth considering.

[village]

In my experience once your iPhone battery starts to do this sort of thing the only real solution is a new battery.

[magirus]

My 7plus (over 3yrs old, 84% battery health) started losing charge a lot quicker than usual a couple of weeks ago. I tried all the usual stuff, none of which worked. I eventually tracked it down to being bluetooth, as I'd started using a Jamjar speaker with the phone and had left it switched on, along with the bluetooth on the phone. As soon as I turned off the speaker and charged the phone up again the problem disappeared.

[Peck]

Thank you gents - much appreciated. We’ll try a few of your suggestions

[David_D]

Interesting! My mother’s iPhone 7 has 91% battery but she’s been saying it seems to go down quickly recently. I’ll have to check if she’s upgraded iOS recently.