IOS14 severe battery drain on SE

My first gen SE battery began dropping like a stone after the 14.3 iOS update. I am an older user and I do not use many apps at all. I would go out with the phone at 100% and two hours later it would be down in the weeds (< 20%). After a complete backup/reset/restore I managed to get it somewhat back under control, and I turned off automatic sw updates. Then I forgot about the iOS issue (I'm getting older - give me a break); got annoyed at always seeing the red "1" on my Settings icon; and "accidentally" updated to 14.4 last week. Then I found and read through this forum. I live too far from an Apple store, so I made an appointment at my local Best Buy through the Apple support website. Showed up at Best Buy yesterday. "Oh, we don't support that older model anymore. Apple doesn't even give us the tools/training to work on it anymore. We've tried notifying Apple several times because people with older phones keep coming in with Apple appointments. It's how they get you to buy a new phone." Best Buy referred me to a local cell phone repair shop. They replaced the battery for $70 at Noon PST 3/6/21. Phone changed from 83% battery health to 100%; showed it had a 71% charge; and hasn't budged from that since then. It feels like a brand new phone, and I'm a happy camper.

I found a post that pointed towards the battery needing recalibration and it seems to have worked. When the phone was displaying 1% I did a soft reboot and it was then displaying 48% which pointed towards calibration being required. We then let it run down completely, charged it up to 100% leaving it charging at 100% for a further two hours. Then I unplugged it and did another soft reboot. We let it run down again and followed the same process as instructed and it seems to be much better.

I've had these problems for weeks now. Yesterday I just had the battery changed. It's like a new phone again. Yes there is obviously a problem with iOS 14 and the way the software reports battery usage but I believe the real underlying problem is ageing batteries and to be fair, I have been using my iPhone SE for over three years now. The replacement cost a mere €35 here in Malta ( Non Apple as there are no Apple stores here). The shop were dubious about changing the battery because the phone software was showing battery life at 91%. However I insisted they go ahead with the swap. Since the full charge last night (14 hours ago ) the battery life is still showing 85%. Before, the battery would have died hours ago. Bottom line..........just replace the battery.

I had all the same problems with my iPhone SE. Since changing the battery over three weeks ago now it's been like a new phone. I get almost two days use after a full charge and the phone is behaving just like it did when new. For me the bottom line is: Forget whatever the diagnostics are showing as there is obviously a problem with iOS 14 and the iPhone SE when reporting. Just bite the bullet and change out the battery. If your phone is over a couple of years old then it's the sensible thing to do anyway. I am quite happy with the outcome now and will probably keep the SE for the next year or so.

The readings you are getting is more about the iPhone not knowing what the state of charge is than any thing else. I fixed mine by letting the phone drain the battery completely down until it shut off several times in a row. This resets the battery percentage calculations so that they read correctly. Picked that up from a tip on another forum. My iPhone SE 1st gen was showing a battery health of 83% and that tip fixed the erroneous state of charge reading, although it didn’t give any help in the battery health area.

My Iphone SE 1st Gen has been completely fine the past few months with IOS14 ever since I sent it in to get the battery replaced. It's a battery problem. Apple doesn't seem to want to extend the warranty on this, but it wasn't that expensive to get it replaced.

The battery diagnostics are next to useless. My SE battery shows as healthy, but it is not. If you want to keep using an SE, get a new battery for it. If Apple want to maintain any reputation for reliability, the really need to provide SE battery replacements for free. iOS 14 drains the battery fast, even it the diagnostics claim the battery is healthy.

I followed instructions on letting the battery drain and fully recharging including an additional 2 hours after 100% then performing a soft reboot. This is to recalibrate the battery and touch wood, it seems to have worked so thanks everyone for posting some helpful comments.

Anyone with a first gen SE that is 2 years old will certainly need a new battery, but the original poster already checked their battery health. Still 2 years is a long time for any Li-Ion battery in regular use.

Another check (from my 9 years experience on here) is to charge to 100% before bed. Power the phone right off. Turn on in the morning and after a couple of hours check the battery usage graphic. The level before and after powering off over that 8 hour period should be within a couple of %. If there is a big drain then the battery has an internal electrical leak.

“....It still loses 10-20% overnight even though it is switched off....”

If the phone is powered off completely (using the slider) when this happens then the battery has an internal leak and needs replacing.

As the phone is well out of warranty there is no adjudicator.

The battery health % is normal, expect 1% loss per 4-6 weeks.

The daily battery life is unusual.

iOS version has no effect, my wife runs a 6S (the SE is a 6S mini) and it lasts several days of light use.

Two things you can do

1. Check for internal battery fault https://discussions.apple.com/docs/DOC-250003357
2. Backup the phone, restore to factory, set it up as new, let it run for a day and see if it still drains

Failure of either means the battery has become faulty

Backup and restore

(1)How to back up your iPhone, iPad, and iPod touch – Apple Support

(2) Restore your iPhone, iPad, or iPod to factory settings – Apple Support

(3) Restore your iPhone, iPad, or iPod touch from a backup

Battery Repair

iPhone Battery & Power Repair

(about £49)

In that case

https://discussions.apple.com/docs/DOC-250003357

a couple things, one, i'd check your battery health, go into settings, battery, battery health, and what is your battery's health percentage thing at, is it low? especially is it below 80%? you can judge for yourself or you can share it in a reply. Another thing to keep in mind is, iOS 14 is a VERY "heavy" version of ios, now, i think it'd be a nice clarification to make actually, which iPhone se? the 1st gen that looked like the iPhone 5? because if its that one then, as i said, ios 14 is VERY "heavy" which might not work very well with such an old phone, like, some people are even saying their iPhone X is slow and has bad battery life on ios 14, so its just a little thought to have. honestly i'd love to respond with more but like, in a situation like this, idk, thats all i can really say, especially with just what was said so far, but i hope this helps or atleast points you in the right direction and if you have any other comments, questions, or just things to say in general, feel free to ask/say them and i or someone else would love to help further

I had this exact issue but have an iPhone 11. Through Apple chat support, they ran a diagnostics on my battery and found it wasn’t iOS 14.01 rather it was apps that were trying to run on it. Ultimately I deleted Netflix, Hulu, Instagram, and they recommended Facebook as well. I waited about 5 minutes and downloaded the apps again. I also update apps almost daily as they’re now catching up to the update. This has helped my battery life considerably. Maybe it will help you?

I had similar issue on my 5SE until 5 mins ago. It seems to have gotten fixed by turning the hotspot off. The battery health is at 89%.