It’s often mentioned that one of the real mysteries is why DJI designed the Mavic car charger such that you need the engine running to provide the >13 volts it needs to function.
This morning, I’m reminded of something I did discover some time ago.
The above is true … however …
- IF your car battery is in tip top condition AND if you’ve just stopped after driven for long enough for it to be absolutely fully charged (AND … probably … a large battery, as I have in my Shogun)
… it may be possible to charge slightly more than 1 MP battery without the engine running, before the car battery voltage drops back to its resting 12v.
I’d add that, because I found there was a slight voltage drop to my cigarette lighter socket that rendered the car charger incapable of charging even with the engine running, and to enable several items to be charged at the same time (some rather hungry items, too) whilst I was driving around Italy during summer 2017, I wired up a couple of 20 amp fused cigarette lighter sockets direct from the car battery into the passenger foot-well.
It was one of these I was using this morning, so any voltage drop in a car wiring loom will have an impact on this.
A socket on a short wire clipped directly onto the car battery terminals would give the best opportunity for a charge. One would need to experiment with your car.
Edit: Of course, if you’ve just been driving, you’ll probably have been charging everything whilst you were.