I'm going on a long trek during July and I would like to power my smartphone during my trip to have a GPS (I will be out of the grid during few days (around 1 week)). I know it is not the best solution but a GPS is quiet expensive and I have one on my phone!. I was looking for a backup battery or something to power my phone myself!
I've tried solar solutions but I'm not very convinced about them. Few days ago, I discovered on Blackberry Cool a very fun kind of hand crank system that can power phones. They call it "Voltmaker". It seems to be very good, but it will not be available until October or November...
I was looking for some help to find a kind of hand crank system (but not a gadget!) or something similar to power my phone!
Thanks a lot for your help!