Hi all, I'm wondering if any of you know whether it's possible to charge the om-d's batteries using a solar charger. Most solar chargers only have a 5.5 volt output, but there are a few that have the required 8 volt output or higher. What I haven't found so far, is a charger for the OM-D's batteries that works on anything other than net current or a car charger. I'd preferably have something that works on USB (or a solar charger with sufficient voltage that mimics a car socket or wall socket). Do you guys / girls know of any such product? many thanks in advance!