Mobile DC charger

[apolyshow]

Good morning everybody,

I am new at your forum, dont know too much and i will apreciate your help if you can offer to me .
One of my customers, need a movable DC Charger to power up empty electric car batteries that cant be moved .
So he needs to charged them just a littkle bit and then drive them to a stable charger for the rest of charging .
Is there someone that could help me find what do i need to build it ?