I used a Goal Zero for TDA ride through Africa. It worked for me, but I also had limited power usage:
- I charged a Garmin 500, and had more than one Garmin 500 so I could alternate. A few hours of directed sunlight would bring back to 100%.
- I also charged up a cell phone. However, my cell phone use was limited, mostly turn on briefly an do an email sync on places where there was 2G/3G/4G.