Iphone 7 [A1778 model] battery issues ios 13.4 and 13.4.1

Question

Level 1

6 points

Iphone 7 [A1778 model] battery issues ios 13.4 and 13.4.1

Repost of https://discussions.apple.com/thread/251246376 [Issue not resolved]

Summary:

updated to iOS 13.4 got battery drain issue.
first thought Siri was the issue.
full reset the iPhone 7 twice (once on iOS 13.4 and 13.4.1) and restarted after every update.
found out that issue is related to model A1778 iPhone 7.
found out that battery drain does not occur when 4G LTE is turned off.

Hi, I'm a long time iPhone uses since iphone 3Gs. Now on the Iphone 11 which it great. I recently gave my son my old Iphone 7. Basically it was wiped. Added a child account. afterwards I didnt do much with it for at least a week. I updated to ios 13.4, but I didnt have a sim yet. When I got the sim then I really started looking at the phone and if it was still working fine. I have had issues with the battery life before after updating. but this time it tends to stick with ios 13.4. I have had the battery changed in 12/2008 and the battery health is now 94% (so peak performance capable).

The first day I gave my boy the phone he didnt do anything with it. I charged it in the evening till 20:29 and just left it unplugged. In the morning it was down to 23%. i then started reading different forums about issues with ios 13.4 and steps to undertake. first one was an advice that is normal with a major update. To him I can say its not normal 77% drain in one night (approx. 12 hours) evening is not normal.

The standard advice Apple gives is backup the phone, reset the phone. So I did. Even though the phone was practically empty, with only one non apple app on it.

Things did seem better. it went down from 77% drain to 20% drain in one night (approx. 12 hours)

but during the day. I told my son to keep an eye on the phone. He only used the phone for 10 minutes to watch an youtube video. After that he checked it once of twice to see how the battery was holding. So after (approx. 16 hours) it was down to 50%. Afterwards we left it there and starting watching a movie on the apple tv. Around bedtime I checked the phone again and it was dead. Battery empty. This is within 24 hours doing almost nothing.

What I did notice was that Siri was doing something 100% the whole time during approx. the last 50%.

I checked the settings and Siri was only on for suggestions. So i'm not sure what Siri is up to. Anyone have an idea? How can I fix this? I have turned of Suggestions and put the phone on charge again. So will have to see if this occurs again. Is this a siri, ios 13.4 bug? or part of a larger battery drain issue people are talking about on this forum? Hope someone can help. and thanks in advance.

[Update 1] Iphone 7 battery issues ios 13.4, siri 100% usage.

Did a recharge yesterday and this morning in just under 12 hours of idle time. battery was down 67%. Yet again Siri was doing something.

All Siri settings were turned off via the settings menu.

Anyone have a clue whats going on? hopefully its a software bug and Apple can fix it asap. Thanks!

[Update 2] Iphone 7 battery issues ios 13.4, siri 100% usage.

Contacted Apple support via chat. Couldn’t find anything wrong. Did do a scan of the phone.

Agreed to do some testing. With flight mode on and low power mode on.

Preliminary results: after approx. 18 hours went down only 1% from 100%.

Have now turned off low power mode to see how fast it will drain now with flight mode still on. Hopefully it will help pinpoint the issue. I will update after 12 hours with screenshots.

iPhone 7

Posted on Apr 9, 2020 2:53 PM

Reply

Answer 1

Best reply

shah2 Author

Level 1

6 points

Apr 11, 2020 2:34 PM in response to shah2

[Update 7] Iphone 7 battery issues ios 13.4.1

Had a chat with Apple support again. great guy helped me out again and suggested I do a SIM swap preferably of another provider. Luckily I had another SIM from work, which is on another network. I was thinking the same thing to test that as well. But I also thought that it couldn't be that could it? Well here are the results and they are actually really surprising!

Changed the sim around 15:54 at that time I had the other sim in my phone with 4G data off. So started off at 80%.

At 23:45 I only lost 4%. so that approx. 8 hours later. with phone on WiFi and idle. Which is great!

At first i couldn't believe what I was seeing! Right you would think come on how can a mobile provider be the cause. When I also have a iPhone 11 on the same network. Okay the technology in the iPhone 11 is far more advanced, but still. Just to be sure I changed my SIM back again and left 4G data on. around midnight.

In the morning bingo! battery drain again. down from 76% to 18%. overnight doing nothing. 58% battery drain in approx. 9 hours. If your compare that 4% in 8 hours and 58% in 9 hours!! both 4G on and idle phones.

Two and a half hours later, down to 6% another 12%.

All things considered, still being skeptical I did a smaller test again by doing a SIM swap again. but same results. almost no battery drain compared to 5% in just over a hour.

You could say hey wait a minute what is Siri doing heavy using the phone. Well thats normal after a complete reset of your phone. Siri reindexes the phone.

Unfortunately due to Corona didn't do any real world testing with the sim swap. Just at home with phone in idle use. So not sure if location played a role. On the other hand look at the reception bars: two bars (4G on and no battery drain) compared to four bars (4G on and battery drain). All things considered I do recall that I have used a SIM from a third provider in the past without any major battery issues with this phone.

Tentative Conclusion: the iPhone 7 [A1778 model] in combination with the sim provider I am using might not be the best combination. I will get another prepaid sim for the iPhone 7 from another provider. At least with the new SIM I hope I don't have this issues anymore and I can use the phone a little longer and don't have to buy a new phone for my kid, just yet.

Reply

Answer 2

shah2 Author

Level 1

6 points

Apr 9, 2020 2:53 PM in response to shah2

[Update 3] Iphone 7 battery issues ios 13.4

Siri 100% usage NOT seeing this anymore.

As posted this morning. 100% to 99% with flight mode on and low power mode on. (idle use) after approx. 18 hours.

After turning low power mode off but flight mode still on. after approx. 12 hours it went from 99% to 95% which I consider normal (idle use). But still not really a usable phone without cellular and data network. Funny side note is that on the iphone 7 Bluetooth stays on when in flight mode and on my Iphone 11 it turns off (both are on ios 13.4)

I have the iphone 7 128GB A1778 (which I found has the intel LTE modem) if you want to find your exact model go to Settings > General > About > next to the Model Number you'll see something with MWMxxxxx if your tab on it you'll see the A number.

Intel LTE modems are A1778, A1784 and Qualcomm LTE modem A1660, A1661. (as found on the internet)

Next up. i'm going to recharge the phone to 100% and then turn flight mode off so that all functions are working. But turn off 4G (LTE) and keep WiFi on. lets see how that goes. Side note I do not use Wi-Fi Assist in the Mobile Data section (Settings).

In the meantime could people respond, who are having battery drain issues with ios 13.4 and leave their iPhone 7 model number as a reply? Thanks!

[Update 4] Iphone 7 battery issues ios 13.4.

Ok so i'm updating my iphone 7 at the moment. So just wanted to post my final results.

Next up. i'm going to recharge the phone to 100% and then turn flight mode off so that all functions are working. But turned off 4G (LTE) and keep WiFi on. lets see how that goes. Side note I do not use Wi-Fi Assist in the Mobile Data section (Settings).

During the night after again approx. 12 hours only lost 1% again of battery life. With most settings on (wifi, bluetooth, background refresh etc) except 4G data off.

During the day I set 4G on again and voila. Battery drain started again. after approx. 12 hours. battery dropped 70%

This was with WiFi on.

Sure to say the issue is with iOS 13.4 and the Intel 4G LTE data modem connection. Apparently a bug that mostly hit the A1778 model. but I have seen such behavior before. So be careful with new major releases it might be buggy with this model.

Solution: update to iOS 13.4.1, thanks Apple!

[Update 5] Iphone 7 battery issues ios 13.4.1

I spoke too soon. I still have a battery drain issue with iOS 13.4.1 last night charged it to 95% this morning was down to 49%.

being idle all night 46% in approx. 9 hours.

I have restarted the phone. hopefully that will be the last thing needed to be done. Will do a full recharge and then see how it goes from there. if not successful I will start a new discussion.

[Update 6] Iphone 7 battery issues ios 13.4.1

Started a new post with all the information I have gathered over the last week. After a restart and full recharge. Still battery went down 23% [idle use] in approx. 6 hours.

Afterwards I did a full reset of the phone and now after a full recharge. It has lost 5% battery life in 2 hours sitting idle on the table. So 13.4.1 isnt a solution for me.

In the first thread all the people who had issues had an A1778 model as well. iPhone 7. At least one confirmed it solved it for him. In all my test the only way to stop the drain is to turn off 4G LTE.

Anyone have an idea what else I can test?

Reply

Iphone 7 [A1778 model] battery issues ios 13.4 and 13.4.1

Similar questions