I have been watching the technology from Goal Zero for about a year now and they seem to have a solid business model. I'm not sure if it would be compatible to charging our Ebikes, but at least the technology for extended trips are out there!!
Thanks James, this is pretty neat stuff. I've always liked the idea of solar chargers and understand that most of the portable ones like the Solio actually have a battery inside that get charged slowly on their own and then feeds into a device like an iPod to charge it up later no matter the conditions. This requires two batteries and a dongle to connect the packs for power transfer... it may also leave the solar powered battery completely drained at the end which could harm the cells.
What if there were an electric bike battery that was mounted to the bike frame but also removable (like the one on the Easy Motion EVO Eco) that had a solar sheet wound inside. You could park the bike, take the pack off and then pull out the solar flap to charge all day! The flaw would be held with a spring at one end like a pull down window shade so it would be easy to wind back in after charging... This would eliminate the need to carry a second battery or dongle because it would all be built right into the main pack. Here's a quick mockup I created to try and communicate the idea along with some existing technology:
The downsides I see here are heat damage to battery cells (Lithium-ion gets degraded with higher temperatures) and also the need to leave your battery laying out in the sun somewhere that people might steal or damage it. Still, in an office you could just put it near the window
Goal zero's products are very useful for some purposes. Charging ebike batteries is not one of them. When you actually do the math it could take many days to charge one bike battery.
This makes a bit more sense-http://www.ogpower.com/product/og-suncycle-ebike-charger/
Unfortunately, you can't take the charger with you-but you can always have extra batteries.