I have the 12v vehicle charger for my mavic 2 pro and it seems to not be working correctly. I plug in a battery into the charge plug and  it sits for a few minutes and then will flash the round green lights on the battery for a second or two then sit  for a little bit then repeat the process. I cannot hardly get one battery to charge using it.  Also if I try to use the charge hub it flashes yellow then green  back and forth.  When I plug my batteries into the wall charger and hub they all charge fine, green lights stay consistently on in the batteries and the hub indicator light.  Any idea what’s going on with it? Maybe a bad 12v Charger?

Its more likely the 12v output varies a lot from the car depending on other electrical loading, engine loading and so on.   Its fairly common that cars dont give a consistent voltage out.  The causes the charger to start and stop.  If you do a lot of car charging, you maybe better off buying an inverter and using the mains charger.

Hello and good day Cmartin3977. Thank you for the inquiry and for reaching out and I am sorry for the trouble. We do not recommend using 3rd party car chargers in charging your DJI Mavic 2 Pro. There is a possibility that 3rd party devices/charges will work, however, since it's not yet optimized with our application and with the DJI Mavic 2 Pro we cannot be guaranteed the stability of the charger if it will work all the time while using it on the said DJI drone. Thank you.

Steven it’s the stock 12v Charger that comes with the flymore combo for the mavic 2 pro. Came straight from DJI

You didn't mention if the car engine was running at the time of charging or not.
A lead acid battery has a normal terminal voltage of about 12.5 volts. This rises immediately after the engine (alternator) stops and quickly drops back to normal.
An older car battery also loses its capacity and the normal voltage drops a bit further.
Your DJI charger has a low voltage cut-off which is about the same as the normal voltage value so that you don't over discharge the car battery and can't start the car. You need to run the engine for continuous charging.
I hope this explains what is happening.

AlansDronePics Posted at 7-21 12:47
You didn't mention if the car engine was running at the time of charging or not.
A lead acid battery has a normal terminal voltage of about 12.5 volts. This rises immediately after the engine (alternator) stops and quickly drops back to normal.
An older car battery also loses its capacity and the normal voltage drops a bit further.

The vehicle was off at the time, But I cannot fathom why Dji would make it so sensitive that you have to have your vehicle running to use it. Not everyone wants to sit there and waste 45min worth of gas  just to charge one battery.  

Cmartin3977 Posted at 7-23 17:53
The vehicle was off at the time, But I cannot fathom why Dji would make it so sensitive that you have to have your vehicle running to use it. Not everyone wants to sit there and waste 45min worth of gas  just to charge one battery.

Even with an inverter, stepping a nominal 12 volts lead/acid battery up to mains voltage still has the same issue, simply because of the way this type of battery works. If you have a perfectly made, brand new l/a battery, fully charged, it dosn't take much current draw to reduce its voltage to a point where a less well maintained vehicle fails to start. Cold weather, large clapped out diesel engine... DJI aor anyone else, can't predict the circumstances of the user, like you. It is just common sense to build the charger with these realistic properties. The alternative might be your family complaining how DJI left you stranded in Iceland because the charger drained the car battery and you froze to death.

Yeah, car needs to be running. I also heard that in some newer cars the 12v socket is limited to 5 amps, dunno how true that is though, only heard it in passing conversation.

Cmartin3977 Posted at 7-23 17:53
The vehicle was off at the time, But I cannot fathom why Dji would make it so sensitive that you have to have your vehicle running to use it. Not everyone wants to sit there and waste 45min worth of gas  just to charge one battery.

The way I "reason it", is that it's intended to charge while your actually driving the vehicle., Just sitting idling is yes, a waste, not efficient.
But smart so you don't end up with a dead car battery...

I noticed the charging was intermittently active and non-active as well.  I was thinking that the adapter wasn't contacting the vehicle contacts properly, due to some bumps during me driving.  But, it did charge the battery though (it was the OEM vehicle charger from DJI that came with the fly more combo).

If you feel your situation and competence demands a different approach, this will do nicely. https://www.amazon.co.uk/gp/aw/d/B0756VVDKT/ref=ox_sc_act_image_1?smid=A3HKSK3TO8O6GX&psc=1
You will notice the device will operate at 10 volts (or more) and step up that voltage to 12 volts or more. The point being that you can adjust your own voltage cut off and output so the DJI charger you would use plugged into your car would keep running until the car battery voltage dropped below the threshold YOU SET.

sounds like have a bad alternator or a failing or internally shorted battery if it is unable to maintain at least 12.5V with the engine on,..  most cars will push 12.5 - 14 volts so pleny of power and well within spec to maintain DJI's charging curve.

It could be that a lot of modern cars now have smart charging. This means that there is not always a charge going into the battery when the car is running. Also if your car recoups kinetic energy from breaking, the charging system will keep the battery at about 80%. The other 20% is where the recovered energy would go. So when you car charger stops working, it could relate to when your alternator stops charging. This is also the reason that when fitting leisure batteries in some modern vehicles, the old tried and tested split charge relay wont work and fitting one will only reduce the charge in the second battery.  If this is the reason, then it is bad design on DJI's part to get an old style car charger that is not compatible with modern auto electrics. If its any consolation, my charger also works intermittently. You can by battery to battery chargers to combat this problem and will produce a constant 14V.

Mark-oo Posted at 8-8 14:13
It could be that a lot of modern cars now have smart charging. This means that there is not always a charge going into the battery when the car is running. Also if your car recoups kinetic energy from breaking, the charging system will keep the battery at about 80%. The other 20% is where the recovered energy would go. So when you car charger stops working, it could relate to when your alternator stops charging. This is also the reason that when fitting leisure batteries in some modern vehicles, the old tried and tested split charge relay wont work and fitting one will only reduce the charge in the second battery.  If this is the reason, then it is bad design on DJI's part to get an old style car charger that is not compatible with modern auto electrics. If its any consolation, my charger also works intermittently. You can by battery to battery chargers to combat this problem and will produce a constant 14V.

my GF's car uses is one of those weird modern BMW systems that is most definitely not always charging her 12V battery, its only charging when your moving and coasting however if the voltage slips below 12.5V i think, the alternator on engine kicks in and takes over..  i never had issues with using a charger in her car unless we are at stop/start sometimes that causes it to freak out for dji battery charger..but turn that off and seems to not have any issues..

ny car has a smart charge system as well but very basic and my car doesn't do stop/start (im thankful for, omg i hate stop/start) and it keeps the accessory outlet alive for 10 minutes after turn off the car..  so ya i dont really encounter any issues with mine even though its allegedly "smart" the system so basic that i dont know.  mine always shows 13V - 14V

HereForTheBeer Posted at 8-8 15:26
my GF's car uses is one of those weird modern BMW systems that is most definitely not always charging her 12V battery, its only charging when your moving and coasting however if the voltage slips below 12.5V i think, the alternator on engine kicks in and takes over..  i never had issues with using a charger in her car unless we are at stop/start sometimes that causes it to freak out for dji battery charger..but turn that off and seems to not have any issues..

ny car has a smart charge system as well but very basic and my car doesn't do stop/start (im thankful for, omg i hate stop/start) and it keeps the accessory outlet alive for 10 minutes after turn off the car..  so ya i dont really encounter any issues with mine even though its allegedly "smart" the system so basic that i dont know.  mine always shows 13V - 14V

I think the problem will be the charger is not compatible with all of the modern auto electrics. Different manufacturers handle it slightly different that's why you'll get some people saying it works fine in this car and others saying it won't in others. I think you'll find that if most people with these "intermittent chargers" were to plug them into an older vehicles 12v socket or a booster pack it'll work fine.

I have a dji 12v charger and it has same problem with no constant charge rate, so I have a separate batt and an inverter and use the 4 bank 240v charger which works fine. I can charge the batt, controller and phone. The inverter does draw 6amp/hr whilst charging so a 60amp/hour batt will give you about
30amp/hr (without damaging the 12v batt) 30 divided by 4amp/hr(flight batt)=7 charges.

The cheap third party car chargers available on eBay or Amazon do a better job. The original DJI car charger is known to need a high input voltage and will typically only work with the car engine running. The cheaper no-names seem to work from 10 volts up. I have one of them and never had issues with it charging my Mavic 2 IFB (same or even lower charging time than the DJI wall charger). No overheating or whatsoever.

I think this is not a flaw in the DJI charger. I think they want to prevent flattening your car battery. It would have been easy to design it with a different input voltage threshold.

- Carsten

Make sure the plug going into the 12v socket is tight, i've had vairous issues with other equiment due to a lose connection in the 12v socket, i've always got around it by putting something in with the connector if it's lose.

Flygrl Posted at 8-9 09:55
The cheap third party car chargers available on eBay or Amazon do a better job. The original DJI car charger is known to need a high input voltage and will typically only work with the car engine running. The cheaper no-names seem to work from 10 volts up. I have one of them and never had issues with it charging my Mavic 2 IFB (same or even lower charging time than the DJI wall charger). No overheating or whatsoever.

I think this is not a flaw in the DJI charger. I think they want to prevent flattening your car battery. It would have been easy to design it with a different input voltage threshold.

I have one of the cheap car chargers that does two batteries from ebay that worked great, I just picked up the genuine charger for travel use,  by the sounds of it I need to do some tests to see how well it works,