DC generators produce a "noisy" voltage signal that might confuse a digital device and make it perform erratically, but I don't think it would damage it in the process. I'd suggest installing a small auxiliary battery such as one of the the gel cell batteries used to power a kid's ride-on toy or something similar, and wire a power port to that. You could get several days' worth of use from a cell phone or other device before the battery would need recharging. A simple toggle switch could be used to isolate the second battery from the generator while electronic devices are in use.
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!