Location services are really an integral part of a ton of iOS apps, using the internal GPS system to add Instagram photos to a map, checkin with FourSquare or Facebook, or let your friends know where you are with one of many “on my way” apps, like Glympse or Twist.
If you’re battery is dying, however, the location services are the first thing you should turn off, as they suck up a lot of your iPhone, iPad, or iPod touch’s power needs, what with their background data sending and receiving and such.
Here’s how to turn them off.
Tap your Settings app to launch it, and then tap on Privacy. You’ll be able to turn the toggles OFF for any specific app that has privileges to access your GPS location by scrolling through the list and tapping them all. I do this on a fairly regular basis for both privacy and battery savings. I figure that with less apps accessing my location, the less battery power in total is being used for that function.
If you want to turn off Location Services completely, then simply tap the main toggle at the top to OFF, and you’ll stop using them. This will keep your apps that need it, like Maps or Compass, from knowing where you are, but the battery will thank you.
Source: Apple Support