If you simply need to charge on the road, then either get an inverter, or the DJI 12V adapter. I vote for the inverter. You don't need to get a very large size. I just confirmed this by using my Kill-A-Watt meter to measure the power consumed by the standard wall charger. I used one battery that was at 80% and another at about 50%, and after letting the charger figure out how much voltage and current to deliver, it settled down consuming about 70 watts. So, any garden-variety 120 watt inverter will work. You can get these for under $50.
If you want to charge more than one battery at once, then the DJI unit that lets you plug in four at once will be of no use because, as already pointed out, it charges the batteries one at a time. I personally find this unit to be useless for anything other than charging all your batteries while you sleep.
I assume that you can get some sort of system that will charge them all at once, but with anything more than two you will need to have a pretty beefy inverter, and the whole setup will not be compact, lightweight, and all the other things you want.
So, get a cheap inverter and see how that goes.
Oh yes, if you want something to recharge the batteries when you are completely away from AC or car power, get a big LiON "jump start" battery. You can get these for amazingly low prices. If you get one with 8,000 mAh capacity, it should be able to recharge 2-4 batteries, depending on how far depleted your
Mavic 2 battery has become.
store.dji.com
