Severe battery drain after IOS update to 12.1.2

Virtually the same issue, although my battery - on one year old iPhone 6s -- doesn't show 100% in Battery Health.

Furthermore the battery icon drops suddenly from levels like 74% to 1% at various times of the day, randomly. Plugging into a wall socket USB slow charge takes it to 25%+ in just ten minutes!

I used to keep charging it whenever this 'battery drainage 1%' took place after the 12.1.2 update but, following posts here, I left it on (wifi+Phone+data) plus normal little usage whilst it showed 1%. It kept working for at least a day without issue.

I have an Ipad Air which upgraded to 12.1.2 automatically and although it has the same apps etc and is always on wifi (no phone) has never shown this 1% effect.

So, for a week after eliminating anything that keeps the iPhone awake - refreshing, fetching, pushing, motion, location, raise to wake etc etc. with the 1% keeping coming back, I and my IT experts humbly suggest that there is an issue with the update to 12.1.2 on the UK iPhone6 and ask Apple to advise us all.

Frustrated with no feedback on this issue from Apple since it was raised on the forum in December. 😒

Hi Deggie,

It's not the usage per-se but the incorrect reporting of 1% battery level. We could see no obvious application using the battery inappropriately - i.e. on or active when it shouldn't have been - during the prior week's testing.

Most people seem to assume the battery is flat and 'recharge' it, not realising that they could keep using it !

An update on my 1% display.

I left the phone on uncharged showing 1% and it took 5 days before it powered down. This confirms that the low battery indicator is a software issue and nothing to do with use of my phone.

I hope Apple will take note and update the software to correct this problem as it is very frustrating not knowing how much actual charge there is in the battery.

I have had the same issue, same phone. My family has 3 other iphones(1 is a 6plus), 2 IPad minis and an IPad. The 6s is the only one with this problem. Maybe you have encountered some with the 1% problem, but that's not the case with mine. It drops and dies, and shuts down until I charge it. I charge to 100%, pull off charger, leave on table with everything possible off, and it will be dead in less than 90 mins. Old battery had 90% life, put in a brand new battery (says 100% life), same problem. Go to usage and shows like 2mins display used on battery, and that's it, and yet battery dies in 90mins. if I don't touch it. If I actually use the phone like I am supposed to,,,,dead in 30-40 Unreal.

@SGM_34 Seriously, stop reposting the same useless nonsense. I have everything turned off, on my iPad Pro. The battery drains to 0% in 1/10 of the time it took to completely drain the battery, prior to the latest iOS update. Apple!!! Fix this **** now!! You’ve rendered our devices useless. There is no legitimate half-*** solution. This needs to be fixed in a new update.

The battery on my iPhone 6, which gets little use, started draining very rapidly. Battery Usage stats showed Mail consuming at 100% for hours overnight, as it sat on the charger (which it does most days too).

I tried changing settings etc., to no effect. However ... it looks like I've found a fix. Delete Mail app, then download/install it again from the app store. This deletes everything in prefs/settings for Mail. So effectively a reset for Mail. Your Accounts are still present, so you can re-activate them by simply turning them on in the Accounts settings.

So far so good, over a relatively short period of time. I shall see how it progresses over a few days of normal use.

(NB ... if you have email that resides 'on your phone', e.g. a POP account, you will have to move it (backup) somewhere else prior to deleting the Mail app, or you will loose your data).

You don't have to surmise, go back to Battery in Settings and see what apps/processes are using the most battery on your iPhone.