Car charging made complicated...

[pbzpln]

Thanks to DJI's brilliant decision to make the car charger only work @13.05v, like many of you I have been trying to find a way to use this hunk of junk without running the car the whole time.

I have plenty of inverters, but the only pure sine wave ones I have are already hard wired to batteries on cargo van, and I don't trust charging something this sensitive off a little crappy square wave one. Besides the one I tried trips with much output unless the vehicle is running. It will run small chargers without tripping. Also the car charger is faster so that would be nice to use.

I checked a fully charged JNC660 jump box, after unplugging from my AC outlet it was at 12.95. Then, light bulb, I plugged the charger back in, and it fairly quickly rose to `13.5v. This is a fairly big jump box, but charges slowly, so I checked and it does not trip my inverter with the vehicle off.

So my plan is to plug the car charger into the jump box, plug that into the inverter, run the car the first few minutes to get the jump box and car battery full and while the car charger has the most draw (I believe it drops some after several minutes). Then shut off and hope the difference between the output of the car charger and the input of the inverter (couldnt find how many amps the JNC660 draws) keep the jump box above 13v till the Mavic battery is charged.

But, but, but, you might run your car battery down...

Yeah but I'm guaranteed to at least have a fully charged jump box to fix that lol.

Yes going DC to AC to DC is ridiculous, but does this seem like a viable solution for me (and for others if they already have a decent jump box)?

BTW I noticed the AC charger outputs at 13.05v, so maybe DJI made the car charger to output at that level to match and didn't want to have to step up the voltage? Still sucks, especially when the specs say 12.3 volts minimum in one place.

 

[Ping^Spike]

Thanks to DJI's brilliant decision to make the car charger only work @13.05v, like many of you I have been trying to find a way to use this hunk of junk without running the car the whole time

Wait.... WHAT?!

I just got my flymore combo last week, yet to try the car charger.

Seriously? The engine needs to be running?!

#WTF

 

[PropPilot]

Yep, they designed it to only operate at the charging or alternator output voltage of 13.8 volts. Won't charge on 12 volts which is the batteries idle voltage. Stupid design. Let the user figure out if they are going to run down their car battery versus designing a nanny into it.

 

[Nightowl702]

I have a small 300 W inverter that I plug my regular charger into. It has always worked fine for me with and without the car running. I dont think I have ever used my car charger.

 

[HFMan]

The car charger is just a stupid power supply- it was never designed to step up the voltage (which is what it would have to do to provide the battery with the full 4.35V/cell capability (that's 13.05 volts). So the car charger simply provides whatever the battery provides... I don't get it....

 

[Hedonist222]

Could you elaborate on sine wave charging?

 

[mpa]

The car charger is just a stupid power supply- it was never designed to step up the voltage (which is what it would have to do to provide the battery with the full 4.35V/cell capability (that's 13.05 volts). So the car charger simply provides whatever the battery provides... I don't get it....

its not diffcualt to design a boost converter, i bought one from ebay for 5$, works well with the mavic charger.
the actual reason why they did this was to ensure the car alternator was running and people dont drain the car battery while the car is not being charged

 

[quick_dry]

just buy a non-DJI car charger from eBay for $10 or so and be done with it, mine doesn't need the car running and I'm sure they all come from the same factory.

 

[pbzpln]

Or spend $0 like I did, and have a guaranteed way to start my car if I do run the battery down, and use the OEM charger instead of risking my bird on a $10 charger.

Also, for those who do a lot of charging with the car off, AC or DC, might want to buy a deep cycle battery for your next battery, like this:

YELLOWTOP® Batteries | Best AGM Deep Cycle Battery |OPTIMA® Batteries

Use these in our work vans to cut keys from without the engine running, last much long than normal batteries.

 

[JeffM46]

Imagine my surprise when I tried to use the car charger on my boat while at dock. The boat's charger was running on shore power but at float voltage which is about 13.1 volts. Of course the DJI charger wouldn't work even though there was no chance of running down three deep cycle batteries. What a joke of crappy engineering.

 

[Randy]

just buy a non-DJI car charger from eBay for $10 or so and be done with it, mine doesn't need the car running and I'm sure they all come from the same factory.

That's what I did, Ebay, $10.35 and it charges batteries all day long without the engine running

 

[Silli]

Genuine DJI car battery charger sucs big time. Need to keep boat engine running for charge battery size of egg... Thats economic and you save the earth Don´t buy this product, seriously.