I have been searching EBAY and several other sites for a battery charger for the Nikon d5100. The problem with the ones there are that they are AC (plug in) chargeable only. I will be in the Redwoods soon on vacation and Yosemite...so I was a charger I can carry in my pocket that is powered by two double a batteries. The ones on EBAY dont say they are compatible with Double A or any other battery to charge the camera batteries, so I dont want to risk buying one without it. (As there are no plugins in the woods. Or the Camper) Can you all direct me to a link or product that will charge on the go?