I would have thought this possible.  But if I use the little adapter to plug my RavPower into a Mavic Air battery it does not seem to do anything.  I used a male to male USB cable to connect them.  I'd like some way to use a battery brick to recharge in the field.  To me, recharging my drone battery is more important than charging something else USING my drone battery.
Thanks!

Hi there, sorry for the inconvenience. To ensure the compatibility and the performance, you are recommended to charge the battery with the original charger that comes with the drone, thanks.

Get the DJI Mavic Air Car Charger

A CW Posted at 2018-6-25 00:18
Get the DJI Mavic Air Car Charger

Considered that.  My primary goal though is to be able to recharge a Mavic Air battery while on a 6+ mile high in back country.  No cars in which to use the charger!

sequitur Posted at 2018-6-28 13:03
Considered that.  My primary goal though is to be able to recharge a Mavic Air battery while on a 6+ mile high in back country.  No cars in which to use the charger!

I see - amazon do sell some power bank chargers that are compatible with the Air batteries. As things stand you can't recharge the MA via internal Type-C - I think the type-C port was introduced on the Air purely to transfer the files from the internal storage to a computer at a quicker speed than micro USB. If you can't find a power bank then the only other option is to buy more batteries.