Extreme Battery Drain After iOS 18.3.1 Update on iPhone 12

Facing the same here, battery drain issue on my iPhone 15 Pro as well after updated to ios 18.3.1.. Battery health also seen dropped from 99% to 97% within only few days after the update.

Same problem but mine charges to 100% then drops to 1% after using phone for a few minutes but the battery keeps going! I can use the phone for several days with it showing 1% on gauge. I have an after-market battery which is brand new a few months ago and had no problems until new iOS. Called support and they would not admit to some bad code in the update (or deliberate sabotage to anyone not using "official" apple parts). Kept blaming my battery. I reminded them of the $500 million settlement against them in 2016 for a similar stunt and it looks like they're doing it again! This will be my last Apple product.

same issue since updateupdate took place last night i was in work which usually my phone will be 80ish % after as i only go on it on my break however since this update left me 6% after work no apps running in background

I will never update again before checking this kind of communities. What on earth happened!?!?

Hard reboot seemed helped me. The one where you need to press physical buttons.

Here the link Force restart iPhone – Apple Support (UK)

I believe that you have battery drain. But the answer to your questions are in the lists underneath the graphs. Please post screenshots of the Apps you’re using. This type of battery drain is usually caused by an app or two that either need updating or delete and download a new copy.

That’s the only downgrade available from Apple or Apple Authorized Service Provider , beta to latest public release. Apple Support and AASP can’t roll back to prior public iOS releases. Even doing a DFU reset installs latest public release.

I'm having the same problem. Upgraded my iphone 12 from 18.0 to 18.3.1 3 days ago and now instead of almost 2 days working on single charge it barely lasts 1 day.

After updating to ios 18.3.1, my Iphone 15’s battery health dropped from 100% to 97% within 11 days. And 2 weeks after that it dropped to 96%. I don’t know if this is normal or not beacuse it is my first time using an iPhone.

I recall, you’re reluctant to share what’s really going on with your iPhone. Sorry to disturb you. If you won’t share it here go to Apple Support and show them your data so they can fix it. But without evidence to the contrary, I’m skeptical of your statements with no actual evidence to support your claim.

Froid wrote:

Haven’t found a solution. I’ve tried everything except what you are doing, rolling back. I go to sleep with 99% battery on 2 iPhones. No background or location activity, apps closed, Bluetooth off, even WiFi off, apps up to date, battery health fine, yada yada yada. And I wake to 2 dead iPhones. Just hoping for a better update soon

Why don’t you charge your iPhones overnight?

Yes…after the latest 18.3 update my iPhone and ipad will not charge rapidly and stops due to battery temps. This is insane! Just spent over $2k for my iPhone 16 Pro and accessories for charging, ipad etc. These updates are becoming useless. So frustrating!

Have you looked at your Battery Usage by App and Activity by App for last 24 hours and last 10 days? That will show what the culprit is. You may have a corrupt 3rd party app causing the majority (all?) your issues.

iphone > Settings > Battery > ignore graphs for now. Please look at the apps and four different views 24 hour vs. 10 day and Battery Usage vs. Activity > look for unusual consumption and app usage per app

Im not saying it is or isn’t an Apple issue, but without the above perspective app(s) can’t be ruled out.

MooMooFutch wrote:

You are basing my usage on that of someone hammering their phone. I’ve not made a phone call on my phone for nearly two years. I use my iPad for most things. Either way, even if I absolutely murdered my iPhone doesn’t change the fact that up until iOS 18.3.2 my battery was draining normally and then after the update it’s noticeably bad.

The last update killed my battery! - Apple Community