Way to charge batter from battery bank without Spark?

[whereisjim]

I got the combo pack with two batteries.
However, still on the road, need more juicy to fly more.
I'm trying to find an option to charge battery on mobile (without wall connector) or using battery bank or car cigar jack power without Spark.

I'm trying to find a way to charge the battery while I'm flying my Spark. I don't see any option, but does any one know if any option?

 

[Mr. Salty]

Here's the Spark forum: SparkPilots - DJI Spark Drone Forum

 

[bspill]

Buy an inverter that can be plugged into your 12 volt auto outlet then plug the battery hub into the inverter