Universal Li Battery Automobile Recharge Options?

[KenO]

Am planning a photo shoot with some others that will be mainly away from AC to recharge our Li Batteries. We will be using an automobile for transport so am thinking of this possibility instead of solar charging.

We all have different mfr cameras and cellphones so prefer a universal solution.

Hope others have done this and have some suggestions concerning what worked best or even what not to do.

Thanks

Ken