I think they start self-discharging after 1 day. Surprised me at first but other folks have told me the same. Expect it’s part of making them last for more cycles.
Didn’t know that. My Phantom had smart batteries but I didn’t see that the Air’s were too.
The standard one that came with it. I plug it into the AC outlet in the truck or an inverter in the car.
Thanks for the AliExpress link. I’m ordering it now