Disable Unused Features
If you use your GPS frequently with all of its features enabled, your battery may only last for a few hours. Disable features you aren't using, such as the electronic compass, track record, WAAS and GLONASS.
Fully Exit the Camera App
Some GPS models have a built-in camera. If you don't exit the camera app after you've finished taking photos, it could drain power. Fully exit the camera app whenever you're not using it.
Adjust Screen Options
Some of the biggest power drains on a GPS device are the screen settings. Big, bright screens can quickly drain power. While you need to be able to see the screen to know where you're heading, adjust the following settings to use less power:
Turn down the backlight. Adjust the timeout setting from "stays on" to a lower increment. Set the touch sensitivity to normal. Enable battery save mode.