I had some issues with battery life, made a couple of changes to the settings that helped immensely. Set the screen to backlight timeout after 15 seconds, turned off GLONASS (works fine on just GPS), and set recording interval to smartrecord (since I have wheel sensors on both bikes anyway). Yesterday I finished a century (using turn-by-turn course instructions, wheel sensor, cadence sensor) with approx 30% battery life left after almost 7 hours.
This is helpful info. Mfgs should provide simple instructions to maximize battery life as it seems to be an issue for many. Make it too difficult to figure out and folks will give up and buy something else.