Why "Home & Lock Screen" consume more than 20% battery life in iOS 8.3?

Hi Lawrence

I've deleted ALL apps. The only stuff on the phone now is what Apple decide to preload the phone with (albeit I think I deleted the U2 album)

My phone signal at home is no different to the phone signal my husband's iphone 4 receives.

So I would expect that the drain on use would be similar.

But his stats tell me that he is sitting 42%. Standby of 1 day 21 hours and usage of 9 hours 45 minutes since last full charge.

That is all I want! I want to have confidence that I can head out in the morning, maybe check emails, maybe drop in on facebook - nothing excessive - and still have the opportunity to show my boarding pass at the end of the day and to be able to fly back home - as I had enough charge to show the boarding pass via the flight company's app. Without having to have a panic about there being no power left.

Could it be the version 8.3 that is causing it?

Is there any way of going back to a previous version?

It's not version 8.3, and you can't go back.

You may have a defective phone. Or your battery gauge may be out of calibration. So check that first:

• Drain the battery until the phone shuts off
• Charge with the wall adapter for 4 hours, and verify that it reaches 100%
• Drain a 2nd time, and charge a second time to 100%

If this doesn't resolve the problem there's a good chance your phone has a hardware issue.

Thanks Lawrence - I will try this and see how I get on!

It's now 00:31 here so am off to bed!

I agree that cell signal strength seems to be a major component of battery usage. I have a 5s with 8.3 with tons of apps and am nearing my maximum of storage at 26GB, so it's not like I'm going lightweight on apps or content. I have been making it a habit to put my phone into airplane mode when I am in a "two bar" signal area so that I don't have to completely reboot when I want to be available or check for messages and calls. It has helped a great deal especially when traveling and with limited access to charging. Also, I have updated to 8.3 on my iPad and iPhone and have seen no difference, so those who are blaming the iOs upgrades are falsely assigning blame to that. Could you give a little more detail on the interaction of Home & Lock Screen and Phone Low Signal uses of the battery when the phone is not being used? Like many others, I am having a hard time understanding why something so innocuously sounding like a Lock Screen should show up as the major battery user, even above the Phone Low Signal use. Maybe Home & Lock Screen needs to be renamed so as not to throw us off the track of how to manage our battery.

Every few minutes a cell phone registers with the cellular network, so the network can find the phone and thus direct an incoming call to the right tower. It does this by listening for a cell tower, choosing the strongest tower, then sending an "I'm here" message to the tower. It adjusts its signal power based on the strength of the received signal. So if the signal from the tower is weak the phone will transmit with higher power. This is not a small difference; at 5 bars a typical phone will transmit only a 50 milliwatt signal. For the weakest situation it will transmit with a 500 milliwatt (1/2 watt) signal. In a very marginal area, where you sometimes lose signal altogether, it will keep trying to find a tower by sending a request asking for a response from the network. It will do this at full power. So if you have no cellular coverage at all your battery will go down very fast unless you put the phone in Airplane mode. Any energy used by iOS itself will be reported aggregated with display lighting as Home & Lock Screen power. It's probably not the clearest way to report it, but I don't think iOS is capable of separating out power used by various subsystems within iOS.

An update!

The next day, I spent an hour on the apple chat facility to get help - and while the very helpful chap (Ashley) guided me through tips to reduce my battery usage, I found I had already applied these on my phone.

The day after this, my internet access stopped working. I took it to my mobile phone provider and they confirmed it was something with the phone, not my contract (swapped sims and worked fine in the other handset), so I went back to the apple store.

I waited to see someone and they took my phone, tried to connect, couldn't - so swapped it.

I now have a replacement handset and there is a huge difference in battery life. It doesn't drain overnight and I can actually use the apps without worrying that I won't have any juice left after 5 hours!

So, not quite a solution for the problem, but it turns out my specific problem was the handset!

I had battery usage, just like yours. Overnight, 30-40% while locked on home screen.

I think it could be iOS8.3 because here's my cause and solution.

I open the Calendar app (or probably any app) don't lock the phone, explicitly. Just set it on the table, while it's still on and showing and leave it for about 8hrs while I go to sleep...

In the morning, 40% less battery - explained in battery usage as due to Home/lock screen.

If I close the current app and lock the screen explicitly and set it on the table (same table)...

In the morning, about 5% battery reduction.

Solution, close the currently open App and lock the phone manually.

It sounds to me, like a bug.

Well, furry, I'd be interested to know what your cell signal strength is. Mine goes down overnight if I leave it manually locked and all apps closed most likely because I only have an average of two bars signal strength. I'll try it again tonight, but I increasingly believe it is not the apps you have, or how many are open, but the cell signal strength. The best test of that is to leave it on, with a few apps in the background in airplane mode or at least with cellular data turned off overnight. Then see what you get.

So, I charged up my iPhone before I went to bed, unplugged it and left the wifi on along with Twitter, FB, messages and the App Store apps. When I looked at it 9 hours later the battery was at 96%. I downloaded some email and checked FB for a few minutes on wifi and put it in my pocket. After three more hours the battery was at 94%. Then I turned the cellular data back on. I had my usual two bars of strength. I closed all the apps and stuck it back in my pocket. Six hours later at 6pm, I looked at my phone and it was down to 67% with no calls made, one or two texts exchanged. The Lock Screen had used 60% of the power, messaging 16%. All other apps less than 10% each. I can only conclude that the cellular data pinging at low tower strength is the culprit for excessive battery usage. It ain't the operating system unless you are wanting an operating system that automatically shuts off your phone when you have less than four or five bars. I'd rather have the say over that and that is why you have the option of turning off the cellular data and using wifi, or putting your phone in airplane mode. Those are all good options, especially the airplane mode. Or you could mercilessly hassle your provider to get more transmission towers and show up at city council meetings to counter the people who don't want towers and are worried about the wireless transmissions.

Our batteries draining so rapidly since the update isn't being addressed.

davehart wrote:

So, I charged up my iPhone before I went to bed, unplugged it and left the wifi on along with Twitter, FB, messages and the App Store apps. When I looked at it 9 hours later the battery was at 96%.

If you unplugged it the phone was no longer on WiFi. WiFi is turned off 30 seconds after the phone goes to sleep to preserve the battery, unless it is plugged in. So essentially there was no data being sent or received. Which could explain the lack of battery drain.

Cellular Data uses power only when sending or receiving data, but the WiFi protocol standard requires continuous communication, whether data are being transferred or not. So leaving WiFi on will consume considerable power, even when idle. That's why it is turned off.

Thanks for that answer. Even with the wifi on and unplugged the phone only used 4% of the battery over nine hours. That's not bad, really. All of this has reinforced the idea that airplane mode is a great way to regain control over the instrusiveness of a ringing, buzzing phone. I'm leaving it in airplane mode for stretches of hours and enjoying life more. When I need to check messages, email or phone I just turn airplane mode off while I view and respond as I need to without the wait of a full reboot. Your answers have been very helpful.

I understand what you are trying to say, but its probably because you spend some time on the home screen and lock screen. Some ways to save battery: turn down brightness, turn off 4G LTE, turn off cellular data.

David Park, I think we have been answering your question at least in part. I have the 8.3 and an not having as much trouble as you due in part to how I am managing my phone in the two bar cell strength area I live in. Also, if you live or work in close proximity to many wifi networks, your phone may be constantly pinging on them in addition to the cell network. To the extent you are seeing changes between operating system versions may be a function of the fact that some of your previous settings have been reset and you need to go in an lock things down again to stop the incessant attempts to connect. Also, it would not surprise me to find out that there are a great increase in this kind of background activity as a way of marketing you to the internet world. More "functionality" and more apps, especially ones that want your location all eat away at your battery unless you stop them. My 32Gb iPhone 5s with 8.3 was consistently using more power than my wife's iPhone 5s with 8.3 and the main difference is I'm an absolute app whore...she has very few. I have more apps with location services that are important for functionality. Since I've been tweaking my settings, my battery life has increased to a more usable and reasonable level where I finish the day at 60%, 30% if I'm making lots of phone calls and texting or using the mapping and traffic apps. I believe it is all about managing in the radio frequency environment in which we find ourselves at any given time.

Hi all,

I have lock screen option off in most of my notifications and my screen set to auto-lock after two minutes. If I don't check my phone every 5 minutes or play battery-draining games, my phone will last 2 days on the battery.

When you have lock screen notifications, your phone screen will turn on every time that app sends you a notification for however long you have your lock screen auto-off option (I believe). If someone messages you every 4 minutes and your lock-screen is set to 5 minutes; your phone will always be lit (using a lot of battery power lighting the display all day).