battery charger via car cigar-lighter?

Hi all,

I am going for a road trip with probably no electricity access during several days. I think I'll have two or three batteries with me, but is there a way to charge them via the cigar-lighter without using a heavy AC-DC converter.

There is no such accessory on fuji's website. And I am no electricity expert, but I think I cannot go with 12v DC in something for 110-220v AC...... No solution?

Thanks a lot!!!!