Re: charge hybrid battery uing portable solar char
First of all the capacity of hybrid battery is pretty small. 700-800 watt hours, not 2 kilowatt hours.
An electric car it is not. The Honda Civic is 144 volts, and 6 Amp hours IIRC, the Prius is a more voltage (277V IIRC), but fewer AH. The purpose of the battery pack and motor in the hybrid is primarily to recover the energy normally converted to heat in braking, and to allow the car to move when hit the gas, even if the engine has been shut off. You'd be lucky to get 4 miles on pure battery. So while you can add solar cells, and they could put a fair bit of charge into batteries in a typical work day, the total energy stored in the battery pack is really of very limited usefulness.
By comparison the battery capacity in the Electric Rav4 is about 28Kilowatts, roughly 35x the energy storage in the hybrid battery.
If you want 2 Kilowatt hours in NiMh cells, you are looking at tripling the weight of the battery pack,and tripling the size. Hybrids are attractive in part because you don't need a great deal of weight or space for the battery pack. On the Honda Civic Hybrid, think 120 C size NiMh's and you will have the right idea.