Lightweight solar recharger for camera batteries

[luminescence]

Hi there,

                I have been looking for the best lightweight portable setup for the solar recharging of camera batteries. I do alot of landscape and travel photography where I go in hiking for a few days etc. There is alot of stuff on the web and one that looks alright is the GoalZero Nomad 7, here .

I have a Panasonic Lumix GH2 which has a mains plug recharger, but with no other outlets for USB recharging or anything like that. It seems that if I get a Panasonic DC coupler, which is used for linking to a rechargeable battery kit, then that should plug into the Nomad kit, as it also has a rechargable battery kit. But I am not sure here either, whether the electricals are compliant.
 

Also wondering about recharging times too. On mains power these batteries can take several hours to recharge depending upon how dead they are. I have seen reviews for some of these solar rechargers where recharging times have been very slow for some people.
 

So, hoping someone here has some experience in getting the right combination of power and travel lightness. Thanks.