That power bank would be handy to charge phone, controller, etc.
You'll need the 12v car charger to charge the batteries with the usual battery connection plug, or charger hub.
Be aware.
You might have power issues from the 12v system.
The chargers normally need 13.1v or something (assume the M2 charger has same needs as my M1P charger).
While the vehicle is running, and the alternator is charging the battery well over the required voltage, all is ok.
When the vehicle is turned off, the voltage will settle in maybe 10 to 20 minutes to around 12.7v or so, and this isn't enough to run my M1P charger, it sort of goes into a 50% cycle on / off, and never did charge a Mavic battery that way.
As I do lots of road trips, camping 4WDing, I made up a step converter plug to be able to do this off a 2nd batter in my rig, a thread post on that info here.
Anyone else having problems charging ANY DJI batteries in the car? They don't want to charge unless the engine is RUNNING. Tried multiple car chargers, over 2 cars, one with a brand new car battery. Even tried a 12v/120v power inverter. Tried Mavic Air Batteries and now my new
Mavic Pro 2. No...
mavicpilots.com
You might or might not need it.
Suggest, now do some day drives / flights to really see what your vehicle will do trying to charge via the car charger plug.
Edit PS. try and charge on the go anyway.
If you charge your
MP2 batteries when stopped and the rental battery is a bit dodgy, it could let you down !