CRITICAL Information for iPhone users

I should add a totally unsubstantiated thought about this.
It's highly unlikely that Apple made this change because backpackers needed it. I suspect they made the change because they wanted to gather location data for their own (or partner) benefit, and too many people were turning AirplaneMode on.
If you haven't already done so, go to Settings->Privacy->LocationServices. Scroll all the way to the bottom and drill down to System Services. Those are clever hidden things that use gps. Those are things that will now be running even when AirplaneMode=ON unless a user has found them and turned them off. More info in the article.
http://adventurealan.com/iphone4gps.htm

Very helpful, thank you, Amy!

Since this seems like the proper place for it, I'll paste in what I commented on the other thread. There's some misinformation going around about battery drain and iOS power management. I used to work at Apple and have followed the technology quite closely, so hopefully I can help. A few things come to mind:

– Turning off Background App Refresh can't hurt things, but it's also not necessary. BAR doesn't give an app a blank check to run whenever it wants—iOS is much more intelligent and restrictive about this than Android and desktop OSes. iOS typically only allows apps to refresh when the phone is connected to WiFi, and prefers to wait until the phone is plugged in. If you're in airplane mode, you don't even have access to data at all, so the OS won't even allow apps to (futilely) attempt a background refresh.

– The above is true for everything that uses data. If you're in airplane mode, the phone won't even attempt to retrieve push email, refresh app data, check for updates, or retrieve push notifications. Now that there's no reason to ever take the phone out of airplane mode, you can save yourself the hassle of turning these things off when you hit the trail.

– Don't quit apps. It's a common and pernicious myth that swiping up on everything at the multitasking screen will increase battery life. In fact, the opposite is true. iOS allows the most recently used apps to keep themselves in memory (RAM), so when you re-launch the app it doesn't have to reach into the main storage all over again. When you force quit an app, you delete that cache and force the phone to do more battery-draining work next time you launch it.

> If you use Gaia GPS (or Maplets, or other mapping apps) and you want to study the map for 20 minutes to plan a new route, and you don't need it to continuously check for location, you used to be able to set AirplaneMode=ON. Now you would go to Settings->Privacy->LocationServices and turn Location Services to OFF.

With Gaia, you could just turn on the "No GPS Until Activated" switch in settings to accomplish the same thing—then it will only look up your location when you tap the "locate" button or if you're actively tracking.

> If you are setup to have JoesCoffeeShopApp bing whenever you are within a mile of a Joes, and you enable it for LocationServices AND BackgroundAppRefresh, then it will now be able to drain your battery even when AirplaneMode=ON.

Well… yes and no. JoesCoffeeShopApp is not permitted to look up your location in the background. As the article you linked states, that permission is only for apps that need to constantly track location, like navigation apps, and if they're doing it you'll see the blue bar at the top of your screen letting you know that the app is using your location. JoesCoffeeShopApp would be need to use an OS service called Passbook, which passively keeps tabs of your location and has its own Location Services permission.

That said, turning off location services for Passbook might slightly boost battery life. I'd have to do some testing to see if Passbook even uses GPS for location though, IIRC it only uses WiFi and cell tower triangulation.

> I suspect they made the change because they wanted to gather location data for their own (or partner) benefit, and too many people were turning AirplaneMode on.

I sincerely doubt it. First, I am fairly well assured that Apple isn't going to sell my location data to anyone. They don't need the money, first off, and secondly if they ever got caught doing that their consumer trust would plummet. It's not a worthwhile business risk, and it's not the type of thing Apple has ever been known to do. I'm not saying they're perfect morally, but I am saying they're not big on sharing information outside the company.

Apple does track your location for certain services (like the abovementioned Passbook), but it does so almost exclusively with passive WiFi and cell tower techniques. iOS doesn't fire up the GPS unless it really needs it. I know many of us have been clamoring for this change for a long time, as have people in the aeronautics community (which probably pulls more weight than we do). My guess is that either this was an accidental change, or it was a response to consumer feedback.

Big thanks to Amy and other folks that have done so much hard work and research helping the rest of us out with using Iphones as a GPS, on long treks, etc.

Much appreciated!

This is an excellent thread. Thank you for all of this information. Extremely useful!

+1

Thank you! Great info here.

Great info Mitchell, thanks.

Another thing the update did is break the passing of GPS data to some third-party dongles. I know it affected some Bad Elf products (but not all). There were a few others as well.

HUGE thanks to Mitchell for the more detailed information. I'll incorporate all of that when I update the article.

If there are other inaccuracies or irrelevant items in the "Battery Conservation Settings for Backcountry use of your iPhone" section of the article (http://adventurealan.com/iphone4gps.htm) please let me know. My goal is to make this as streamlined and accurate as possible. I think some or many of the items in the "Adjust the settings to optimize for battery life" are irrelevant – they don't hurt, but they probably make no difference. The shorter the list of tweaks to the Settings the better, so I'd like to clean it up.

Thanks, amy

thanks all for this great info!

quick question on Gaia, I found the "No GPS Until Activated" switch, my question is if I tap the locate button, does it automatically turn the GPS off after a certain amount of time? same if I want to do a short track and finish the track?

I'm also assuming that I would leave Gaia GPS on Always in the Privacy settings using the above switch instead?

thanks in advance

Mike

I wish Apple would put the GPS chip in their Touch or iPad Mini without phone capability.

"I wish Apple would put the GPS chip in their Touch or iPad Mini without phone capability."

Doubtful. But that's where a Bad Elf dongle will work.

Hey Mike,

It's probably better to think of the GPS as "active" and "inactive" rather than "on" or "off." It's not like WiFi, which when turned on is constantly searching for a signal. The GPS radio only turns on when an application requests it, even if the GPS feature is constantly enabled.

My understanding is that the "No GPS Until Activated" switch causes Gaia to only turn on the GPS radio long enough to get a single location, except when actively tracking. But it would be worth checking with Gaia to be sure about that. Here's an article that provides some answers, though not all of them:

http://help.gaiagps.com/knowledgebase/articles/170061-reduce-battery-loss

Mitchell- thanks, after reading that article, sounds like no worries of continuing to run

Mike

Two months ago Mitchell wrote: "Don't quit apps. It's a common and pernicious myth that swiping up on everything at the multitasking screen will increase battery life. In fact, the opposite is true."

We recently updated the iphone backpacking article, and I left in the recommendation to quit all apps at the start of a trip. I was planning to take it out based on Mitchell's comments, but here are two things I learned that made me leave it in.

1. In theory when an app is using Location Services in the background you'll get a blue banner at the top of the screen, so you won't be surprised to find out you've got an app draining the battery using Location Services. This is true when I've got Google Maps app running in navigation mode in the background. But, when I turn on Tracking in Gaia and put it in the background, there's no blue banner, and Tracking is a big battery drain. So it is still the case that a user could play around with mapping apps prior to a trip, and not realize that something is still active. It's safest to shut everything down at the start of a trip so there aren't lurking surpises.

2. A few weeks or a month ago I downloaded an exercise app (FitStar) and played around with it for a couple days. I didn't like it, so I stopped using it but didn't shut it down or delete it. Yesterday I went to Settings->General->Usage->Battery Usage and learned that in the prior 24 hours FitStar was responsible for 25% of my battery usage. I don't know what it was doing for me, but I do know that I hadn't opened it in a few weeks.

Consistent with Mitchell's comments, I don't recommend shutting down apps every time you use them. But house cleaning prior to a trip is still, I believe, a good idea.

The updated article is now posted: http://adventurealan.com/iphone4gps.htm

Will IPhone 5 support iOS8.3 ?

Eric – yes. iPhones 5 and 6 can run 8.3

I am running 8.4 on my 4S, so… :^)

Well I learn something new every day. Thanks Larry. My iPhone 4 is maxed out at iOS7.1.2, but the 4S will run iOS8.x

I found this comprehensive list: http://www.everyi.com/by-capability/maximum-supported-ios-version-for-ipod-iphone-ipad.html

And yet another thing to update in the article. Sigh, it is never ending.