The built in 12 VDC to 44 VDC converter is the key to solar charging your PIM e-Bike. Why charge with 12 VDC? Well how about camping in remote areas, or while driving to the ride. The picture attached is a Goal Zero Yeti Lithium storage system connected to a Boulder 100 solar array. The day I took this picture the solar panel was producing enough power that the Lithium pack did not have to supply any while charging the PIM.