Android: Does leaving GPS enabled affect my battery?

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I often help out and regularly read forums and articles about Tasker for Android. One of the things I come across often is people using Tasker profiles to enable/disable GPS when opening specific apps such as Maps, Navigation etc. Or when creating a task set in Tasker with the ‘Get Location’ action to get a fix on the current position.

So what are the negatives about leaving GPS disabled?

  1. If you leave it off, then you have to enable it before loading up any app which will use it such as Google Maps. If you don’t you’ll get a prompt asking you to enable it
  2. If you use Tasker to enable it when opening an app, GPS is not initialized before opening the app. So you’ll still get that annoying prompt
  3. Most location based services from Google such as Now cards etc use the new api which uses cell tower & WiFi locations to determine your location with good accuracy. So it’s only really third party apps which will use the GPS service in the background
  4. The phone will record the last GPS fix and will use this to make getting a new fix on satellites faster the next time the service is started. If you disable GPS you’re starting from a cold start and it may take longer to get a positive satellite fix.

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Don’t be fooled. The GPS service on your Android device is only being used when you see the icon in your notification bar, it’s not always running and draining your battery.

Whilst I can’t comment pre-Gingerbread (it’s been so long since I ran a <=Froyo I just can’t remember). However, Gingerbread and JellyBean have all been pretty good at only initializing the GPS process when requested by an app or the system. In effect, what this means is if you keep control of your applications that you know will ask for GPS and limit these then you shouldn’t see much GPS usage at all.

I have left GPS enabled for years, and I just maintain within each app whether I want it to have access to my location. So for Facebook & Twitter I have disabled the location services from within the apps themselves. I have 34 apps on my phone which utilise the ‘Precise location (GPS and network-based)’ permission, of which most are weather updates or Google Services which i know do not use GPS but instead the cell based api. Other apps like Endomondo I know uses GPS and I’m happy with that as it only uses it when the app is opened.

 
Tip: You can find apps permissions in ‘Settings-Applications’ and then clicking on the app and scrolling down on the app details page. You can also install an app from the Play Store called Permission Friendly Apps. This app scores your installed apps based on their permissions, it can even filter apps with a particular permission such as the ‘Precise location (GPS and network-based)’ permission.

So can you leave GPS enabled? Sure, as long as you are aware of what apps will utilise GPS and keep on top of their settings there is no harm in it. There may be the occasional usage that runs in the background. But in my experience it’s infrequent and only for a short period that it’s more hassle to disable and enable the setting than to just leave it open for use as required. I’ve not noticed a significant drain on battery so I always recommend just leaving it enabled.

Android: Why does Google ask me to turn on WiFi for location services?

A recent post on Joao Apps AutoLocation FAQ made me realise just how common this question is, and how some people don’t realise why it is asked. So why does Google need WiFi on and doesn’t this cause unnecessary battery drain?

I’m going to quote Joao on his FAQ post and share it as it gives a good insight into something which is not necessarily obvious.

If you want any kind of reliable location service to work on your device, you’ll have at least a bit of battery drain, there’s no way around that.

The reason you need to have Wifi on is this:

  • Google knows where Wifi networks are located
  • When monitoring Geofences, your phone will look for nearby Wifi networks, and send that info to Google
  • Google will check their data base and see where those Wifi networks are located
  • Google will report back your approximate location on your phone based on that info

So, your locations will only be accurate if:

  • Your Wifi is turned on
  • There are Wifi networks around you
  • Google knows about these Wifi networks
  • If any of these conditions are not met, your location may be way off.

Obviously this is more tailored to users of his AutoLocation App. However it is still relevant as Google use location awareness for a lot of things in the background of your phone such as weather updates and Google Now cards, as well as passing this data onto other apps like FourSquare, Twitter, Facebook etc.

So next time you get this popup and wonder why, hopefully now you’ll know.

Source: Joao Dias on G+ & Joapps.com Autolocation FAQ