Someone asked me how to charge off solar. This system is designed for parts that are off the shelf. It is not very efficient. If you have an RV battery, or a trolling battery, it's easier. The solar panels are cheaper. What you save makes it hard to build the system from scratch. With the Hobby King type batteries, LiPo, it's much simpler. The chargers are 12v so you can recharge a small battery with the sun. There's a woman going cross country with solar. Not sure what here charge system or battery system looks like: http://electricbikereport.com/cross-country-solar-electric-bike-tour-video/ She is using the light and flexible panels in a design discussed on EBR a time or two. Good luck to her!