- The display uses a lot of energy, so use it as little as possible. The voice navigation will make sure you don't need to check the map.
- Turn off Wifi*, so your mobile phone won't keep searching for it
- Turn of synchronizing services, so that your emails, contacts, etc. won't keep updating
- Using your phone and listening to music eats up energy as well, as does using other apps in the meantime.
- Depending on your phone you can deactivate mobile data, use only GSM or switch to flight mode* entirely, so that only your GPS remains activated
- iOS: If you don't need internet, set Voice & Data from 3G to 2G (Settings -> Mobile -> Voice & Data). Especially in an area with very low reception, your phone might otherwise keep trying to connect and thus use up energy
*(not recommended for iOS devices - Apple also uses Wifi to determine your location)