Thats been my thinking as well I’ve been debating all the various chargers and there are many out there, but Ive been think of possibly getting a decent size solar panel 60 to 85 watt, a deep cycle battery and a inverter and mounting the whole thing on a two wheeler so I can easily move it around with the battery providing enough weigh to stabilize the whole thing in most wind conditions. Such a rig would give you some real usable power enough to even charge cordless power tools.
This is the one I am very close to ordering. Just haven’t done it yet. My daughter got married yesterday.
http://www.batteryjunction.com/md-1600l-combos.html
A 6 kw solar power system is in process of being installed on my place in Yuma.