Charging MVP2 Batteries in Car

[Inspirephil]

I purchased an inverter for using in my car and it works great. And I can charge other things on it too. It allows me to use 120volt items as well.

 

[Thomas B]

Easier to use a charger that plugs into the cigarette lighter if you have the car with you. Multiple chargers out there that do and wil charge 4 batteries simultaneously.

 

[DanMan32]

You have to watch out for wattage/current though.

A single M2 battery charges at around 65 watts. At 12v thats about 6A, more if you count losses if you're using an AC charger with an inverter.

Most 12v outlets are limited to 120W, which is 10A so you might get away with 2 batteries simultaneously if you have a "heavy duty" outlet, but any more than that and you need a more direct connection for the inverter.

 

[G Randy Brown]

I have a MA2 and need a solution for my motorcycle when on road trips.
I know nothing about this stuff but wondering if I could go from say 20% to 100% with 4 batteries (1 charge each) with this charger.
Thanks,
Randy

 

[joeruby]

Note that I am using short 10 gage wire to connect the inverter directly to the fully charged Jeep battery. This is important as the inverter will turn off if the battery voltage drops below 11.0 volts. I suggest you do the same calculation using your drone battery capacities and your motorcycle battery capacity. Then you will have a better idea of what you are trying to accomplish.
I hope this helps some.
Joe
KC7GHT

 

[MAvic_South_Oz]

..
Oldish thread, hopefully they've solved their charging issue.

Another option . . . see this post . . .

Charging Batteries in Car?

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

What I found is the DJI charger (mine for M1P, pretty sure M2 will be same) needs a bit more power than the normal rested 12v car battery delivers.
Without a step converter, mine will charge after turning off the vehicle engine for about 5 mins, before the volts settle to 12.7 / 12.8 or so.

The M1P mains charger at least outputs 13.05v, which is not enough from a 12v resting vehicle battery.
13.8v step up does the trick.

Of course one can use their mains charger and a decent inverter, I've just always liked 12v off grid, and as I have found it is faster too.

 

[Dogpilot]

Personally I use the actual DJI 12V charger. Its max draw is 6.5 amps per hour. It seems to charge my M2P batteries in about 30 minutes from 25-50% to full. So it will at max rate draw 3.25 amps from the battery. This is a bit on the high side, since the charger actually tapers the charge at the end. even so your battery should be able to do at least two batteries without issue. To put it in perspective; a typical car stereo will draw 5 amps, only 1.5 less than the charger. Most folks would not worry about running the stereo for 30 minutes. Unless your battery is soft, it should not put you in any danger of not being able to start after charging a couple of batteries.

Charging through an inverter is the least efficient way to do it. Inverters are inherently not efficient. They also have an idling draw with nothing connected. So you most likely be using 25% more power to do the job. Not that doing a couple of batteries off the car battery would kill it.

For example, an average automotive battery might have a capacity of about 70 amp-hours, specified at a current of 3.5 amps. This means that the amount of time this battery could continuously supply current of 3.5 amps to a load would be 20 hours (70 amp-hours / 3.5 amps).