Car Charger more powerful than AC charger

[DanMan32]

For a while, when I could get it to work, I would swear that the car charger charged the M2 battery faster than the AC charger.

Looking at the specs on the chargers, turns out I am correct.
The AC charger is rated 60W and only puts out roughly 3.5A.
The car charger though puts out 4.5A.
Input voltage/current on the car charger makes it a 91W charger.

I also swore the RC charged faster with the M2 battery using the powerbank adapter.

If you are charging your RC at the same time as the M2 battery, it may take even longer, unless the charger runs at a higher wattage under that load than it's rated for.

 

[impetus_maximus]

one thing to note about the car charger is the input voltage to keep the charger from shutting down.

*no i didn't make the videos.

ideally you want a voltage regulator on in a charger like this that will boost voltage to where it needs to be, but cut it when the battery gets to around 11 volts. (so you can still start the vehicle.) unless you are running your vehicle i wouldn't count on the current DJI car chargers. not without an in-line regulator that is.

 

[DanMan32]

I did indeed encounter where the charger didn't seem to want to stay on unless I had the car fully on. I can't say 'running' because I have a Prius. Many cars these days won't keep the power port on without the car at least in ACC.
But even with the car fully on, the charger kept disconnecting.
I've sometimes had trouble with the power port so I'm going to test with my dad's variable voltage power supply and test cutoff, and if I do have a contact problem to the battery/hub.

 

[impetus_maximus]

Prius? i would suggest mashing the throttle down. drive fast and take chances to keep the combustion engine going then.

 

[DanMan32]

Just watched the video. My concern with his regulator is that it only seemed to supply or draw 2A, which probably means it will take twice as long to charge the battery as the AC charger. He said the regulator could provide 10A.
For the original test, even at 6A, he's got quite a bit of a voltage drop.
EDIT: He has a 0.5v drop (13.8-13.3) with 6A running through resistance causing the drop. That yields 0.083 ohms wiring resistance.

Charger was probably intended to be used with the car running. The alternator and it's regulator would provide a fairly constant 13.8, perhaps as high as 14.

 

[impetus_maximus]

i wouldn't worry about that. the voltage supplied to the charger is enough for the internal charging system (in the aircraft battery) to work. i'm *pretty sure that as voltage goes up, the amps or current drawn in the system will go down.

*not an electrical engineer

 

[DanMan32]

With devices drawing a specific amount of watts, indeed when voltage goes up, current goes down. But I suspect the battery can tell the capacity of the charger and charge more slowly if it has to.
Car charger specs say 14v 6A, and his first video confirms it. But with his regulator, current drops to 2A to the charger, yet his test power supply reads 6A?

 

[CCDD]

Prius? i would suggest mashing the throttle down. drive fast and take chances to keep the combustion engine going then.

I’ve heard you can use the Mavic 2s battery to charge a Prius, you can expect approx 30 minutes of driving time from each battery used.

 

[DanMan32]

Gee, I wish. Then I could just about get to work on two batteries and save lots of money on transportation energy.

 

[lolo780]

Late model BMWs will keep the M2 car charger happy with engine off. At the same time I found out the low temp charging cutoff seems to be higher as the charging stopped early as the cabin temp dropped while parked outside. Warming the battery slightly completed the charge cycle.