It’s iOS showing you something about what it’s doing, not an app in its own right.
Interesting—that’s pretty close to my readings. But I doubt I have any radio interference here at home beyond the usual residential Wi-Fi and fridge motors.
For another data point: I don’t recall ever seeing “No Cell Coverage” in the Battery Usage by App list, and it currently does not appear on the “Last 10 Days” list. I have an iPhone 13 Pro Max running iOS 17.4.1. I will also add it is entirely possible I have been within range of cellular coverage continuously for the last 10 days.
Here’s another data point. My no cell coverage is a lot lower than yours (~10%), to my big surprise. I work in a location where cell reception (all of it, not just “5G”) is spotty at best. This is on T-mobile. Verizon is better, but not by a whole lot. But then I’m in and out of heavily radiation shielded bunkers (think several feet of fortified concrete [sprinkled with baryte] plus lead and poly) all the time. When I’m in there, there is zero reception on any network.
Back in the day my iPhone would get on cell over wifi a lot since we have very good wifi coverage almost everywhere indoors, especially in those radiation areas. However, during the past year or so I’ve noticed that often my iPhone 15 will not get onto cellular over wifi even though the wifi network is there and reception is strong with easily ~80 Mbps transfers clocked. I don’t know if this has to do with our network and/or cyber security people (rumor has it they’re not the greatest fans of cell over wifi) interfering or just that the wireless network itself shows at times too much latency and so it doesn’t get picked for cellular traffic.
But bottom line, I get a lot of missed calls going to voicemail because I’m out of cell reception and my iPhone 15 spends a lot of time with poor signal trying to reconnect to a cellular networks. But the toll it has on my battery seems substantially lower than what you report. I’d second @xdev’s suggestion to have Apple run some diagnostics on it and make sure that everything with your antenna and cell radio checks out.
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If only Apple’s remote diagnostics could do this, but no…
Sometimes my iPhone 15 Pro consumes a fair bit of power while not being active, and I suspected that it might be trying to maintain connection with the cell network while the signal is poor. My house does not have good cell coverage indoors, and it is almost non-existent inside my office. (I do not have an active 5G service.)
The typical power drain of my iPhone looks like this (note the rather steep slope of the curve):
Thanks to this discussion, I finally got to work on a shortcut I meant to try for a while: Turn on Airplane Mode when connected to home or office WiFi, and turn off Airplane mode when disconnected from these networks. The resulting improvement in power consumption is much more satisfactory (the mostly flat line of the curve towards the right):
So far, the only downside to this setup is that the Apple Watch will also switch to Airplane Mode and no longer able to unlock the Mac. Also, I cannot receive SMS via the cell network. I have not found the latter problematic since I rarely receive text messages nowadays (except through iMessages and other apps).
FWIW, you can turn off “mirror iPhone” in watch app / General / Airplane Mode. This means when you really want airplane mode on the watch you’ll need to turn it off manually, but that’s never a problem for me.
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To report back, turning off 5G and forcing LTE seems to have made no difference for the last three days.
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Would you mind sharing your shortcut with us? I have a need for a similar task
Cheers
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My rural area has no and very weak cellular signals so I get the same problem in my iPhone 12 mini. I just use airplane to disable cellular when at home and keep wifi (and its calling) on.
I’ve had this problem since I switched from AT&T to T-Mobile almost 2 years ago. T-Mobile claims 100% coverage across our home area but I get almost no signal in our home and variable signal with 1 mile. For example, right now my iPhone shows SOS for cell signal strength.
My usage shows that the phone is using battery to try to find cell coverage far more than any other activity. I have formed the habit of switching airplane mode on when I am home and off when not.
The two broad steps of creating the Airplane Mode automation are:
- Create two Shortcuts for turning Airplane Mode on and off
- Create two Automations that toggle the respective Shortcuts when the iPhone joins and leaves the specified Wi-Fi networks, respectively
Specifically, the steps are as follows. First we set up the Shortcuts:
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Launch the Shortcuts app, and from the Shortcuts tab, tap the “+” button.
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Tap the “Add Action” button.
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Search for “Set Airplane Mode”, and tap the button.
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“Turn Airplane Mode On” appears by default. If you are creating a Shortcut to turn Airplane Mode off, tap the “On” caption and ensure that the indication is “Off”.
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It is good to rename the Shortcut to tell which Shortcut turns on the Airplane Mode, and which one turns it off.
Repeat steps (2) to (5) to set another Shortcut to turn Airplane Mode off.
We have completed setting up the Shortcuts. Now we proceed to create two Automations, one for activating Airplane Mode when the iPhone is connected to selected Wi-Fi networks, and another one for deactivating Airplane Mode when disconnected from the networks.
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Go to the Automation tab, and tap the “+” button.
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Search for “Wi-Fi”, and tap the Wi-Fi option.
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Firstly, select the Wi-Fi networks which you would like to have Airplane Mode activated when connected. Secondly, select Network Joined when you are creating the first Automation to activate Airplane Mode, or select Network Left when creating the second Automation to deactivate Airplane Mode. Lastly, choose whether you would like to have the Automation run immediately or upon confirmation. I let the Automation run immediately as it gets tiring after a while having to manually trigger the Automation.
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Tap “Next”.
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Select the Automation that activates Airplane Mode for the first Automation, and the one that deactivates Airplane Mode for the second Automation.
Repeat steps (6) to (10) to set up the Automation that deactivates Airplane Mode when disconnected from the specified Wi-Fi networks.
We are done, and now you should see two Automations like my screenshot under step (6).
If you are using the Apple Watch and would like to decouple the Airplane Mode setting from that of iPhone as @ddmiller suggested, you can perform these additional steps in the Watch app in iPhone:
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Launch the Watch app and select General > Airplane Mode.
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Turn off the Mirror iPhone toggle.
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Brilliant description - thank you
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It has nothing to do with the cellular radio. The GPS radio is talking to satellites in low earth orbit, about 150 - 200 miles up, not cell towers at most a dozen miles away. That requires 2 orders of magnitude (power needed increases at the square of the distance) more power. This has always seriously impacted battery life.
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Well, the GPS signal is receive-only on the ground. The satellites do not interact with the millions of devices down here. No phone transmission is done to receive GPS.
Connecting to a cellular tower is a two-way dialog. I would not be surprised if the initiation protocol involves increasing the phone transmitter power in order to search for a connection. The initiation protocol for WiFi might also involve an algorithm for temporarily increasing phone transmitter power.
There are “satellite phones” which do interact directly with satellites, such as the Iridium constellation, in orbit. These use a two-way protocol and moderately higher phone power. The constellations support a more limited number of subscribers (compared to terrestrial cellular) due to limited spectrum and transmission power supported by the satellite.
I should leave a wikipedia link that discusses cellular protocols, but I can’t find anything really applicable.
Here is a link to LTE-3GPP standards:
http://lte-3gpp.info
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You (and @ant) can easily automate this. I have the same problem with somewhere I visit a couple times a year and created ‘personal’ automations in Shortcuts:
You don’t need to create an actual shortcut, just go straight to the automation tab. Create a new one (+ in the top left) and use the Arrive trigger then add the following actions:
Next create another automation with a Leave trigger and the following actions:
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Thanks. I also turn off my privacy for privacy reasons most of the time. ;)
I drove up to and back from the summer house yesterday, there for an hour or so, and I’m seeing “no cellular coverage” in the list now. Only 2% for me.
So I’d say that for me it’s because I was driving through and in areas of very low coverage, yes. The route up goes through lots of areas of low to no coverage.
Thank you! I have not used Shortcuts before and it took some trial and error to work it out but this seems to do the trick. Much appreciated.
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Just for fun, I asked ChatGPI and MS CoPilot. I tried to attach them to this reply, but don’t see how to do it. Just paste “How much battery life does No Cellular Coverage consume for your iPhone?” into each and see what they say!
Is that carrier-dependent? I don’t have that option. (My carrier is US Mobile, a Mobile Virtual Network Operator.)