To save battery in your iDevice you can disable location history by following the seven steps below.
Step 2 Tap More in the tab bar alongside the bottom.
Step 3 Now Tap the Nearby Friends section. (If you don’t see this option, then Nearby Friends nor Location History are live in your area yet).
Step 4: Tap the gear icon.
Step 5: Choose Location Settings.
Step 6 Tap to turn Location History on or off.
Step 7 After disabling Location History inside the app, you also should change location access for Facebook’s app on your iPhone from ‘Always’ or ‘While Using the App’ to ‘Never’, as outlined further below.