Charging Batteries in Car?

[ChrisOutdoors]

If you have problems, get hold of a step converter to boost the ~ 12.7 resting volts, to 13.8v output.

I made this using suitable dual core cable, an inline fuse, and a heavy duty M & F cigarette lighter plugs . . .

View attachment 97794

It will charge my drone when I'm off grid from any of my heavy duty ciggy sockets in the 4wd, even down to low 12v on the 2nd battery.

An example I just found on ebay, ex China . . .

NEW Voltage Booster Power DC Converter Step Up Regulator 12V to 13.8V 20A 276W | eBay

Output power: 276W. Output current: 20A (rated working current in a long period). Industry grade DC 12V to 13.8V step-up converter. Simple to install. More than 95% power conversion efficiency. Ultra compact size, light weight.

www.ebay.com.au

Edit - PS. the 12v DJI car charger has my M1P batteries charged far faster than the mains power charger.
This seems the same with a lot of things though, like my Ryobi One tools, those batteries charge up noticeably faster on the 12v charger too.

@robgallo listen to this guy, this will likely work as you're probably having voltage problems.

 

[GadgetGuy]

Can you charge other devices when the engine is not running ?
In some vehicles the charging port is connected to the ignition so doesn't work unless the ignition is on, some care audio systems are the same, it stops things draining the battery if antecedently left on when the vehicle is left unatended.

Exactly! If that is the real problem (depends upon the vehicle), no step converter by itself will solve the problem. You'll need to rewire the cigarette lighter socket directly to the car battery, to bypass the ignition, so it is live when the ignition is off.

 

[MAvic_South_Oz]

Of course it goes without saying that the cigarette lighter plug needs power, usually MOST vehicles in the World have an accessories setting on the ignition.
One would assume someone using the 12v charger in their vehicle is going to know this.

The problem of the DJI car charger, is it needs higher than resting 12v battery volts to actually work as it should.
When the vehicle is turned off the charge is immediately around that of the vehicles alternator, 13.8 - 14.0, sometimes higher with an upgraded diode fitted.
The DJI 12v charger will function perfectly well, during the time the vehicle is running, until it drops to a level it will no longer operate reliably.
Anything from 5 mins to say 15 minutes, and the battery voltage settles to the usual resting 12.7 or so.

When I first started using the 12v charger, I found no problems when driving, or shortly after stopping and turning off the engine.
When it dropped too far, the charger entered like a cycle mode, the battery cahrge idicator might flash for 30 seconds, then stop for 30 seconds, but I never had one fully charge in that state.

I run my step convertor off a 2nd battery, that charges from the vehicle alternator, or using a solar panel if camping for more than 24 hrs.
I'm certain charging a couple of my M1P 3830mah (3.83ah) even from my main battery would be no issues, even if parked for that time, it's usually only part of that capacity too, if flying down to the usual 15% or 20% battery level.
Of course this depends on a good reliable battery fitted as the vehicle starting battery.

This could vary with other DJI products.
My Spark will charge using the 12v charger for that with any normal level of 12v power available, even if the battery is in resting voltage state.

 

[GadgetGuy]

Of course it goes without saying that the cigarette lighter plug needs power, usually MOST vehicles in the World have an accessories setting on the ignition.
One would assume someone using the 12v charger in their vehicle is going to know this.

The problem of the DJI car charger, is it needs higher than resting 12v battery volts to actually work as it should.
When the vehicle is turned off the charge is immediately around that of the vehicles alternator, 13.8 - 14.0, sometimes higher with an upgraded diode fitted.
The DJI 12v charger will function perfectly well, during the time the vehicle is running, until it drops to a level it will no longer operate reliably.
Anything from 5 mins to say 15 minutes, and the battery voltage settles to the usual resting 12.7 or so.

When I first started using the 12v charger, I found no problems when driving, or shortly after stopping and turning off the engine.
When it dropped too far, the charger entered like a cycle mode, the battery cahrge idicator might flash for 30 seconds, then stop for 30 seconds, but I never had one fully charge in that state.

I run my step convertor off a 2nd battery, that charges from the vehicle alternator, or using a solar panel if camping for more than 24 hrs.
I'm certain charging a couple of my M1P 3830mah (3.83ah) even from my main battery would be no issues, even if parked for that time, it's usually only part of that capacity too, if flying down to the usual 15% or 20% battery level.
Of course this depends on a good reliable battery fitted as the vehicle starting battery.

This could vary with other DJI products.
My Spark will charge using the 12v charger for that with any normal level of 12v power available, even if the battery is in resting voltage state.

I'm convinced your recommendation is the solution to my problem, too, as mine seemed to stay on initially, after shutting the engine off, but stopped charging shortly thereafter. I've ordered the recommended step converter, and looking forward to charging while flying! Thank you!

 

[MAvic_South_Oz]

I'm convinced your recommendation is the solution to my problem, too, as mine seemed to stay on initially, after shutting the engine off, but stopped charging shortly thereafter. I've ordered the recommended step converter, and looking forward to charging while flying! Thank you!

No problems.
Easy to find the similar size dual core wire to suit*, and M/F plugs, but of solder, shrink tube, and done (edit, don't foget that fuse !! ).

*Keep wiring as reasonable short as possible, to avoid voltage drop, but the wires are pretty decent coming out of the convertor.
I used same dia wire.

Just measured mine.
36" / 91.5cm to the male plug
20" 50cm to the female plug

 

[GadgetGuy]

No problems.
Easy to find the similar size dual core wire to suit*, and M/F plugs, bit of solder, shrink tube, and done.

*Keep wiring as reasonable short as possible, to avoid voltage drop, but the wires are pretty decent coming out of the convertor.
I used same dia wire.

Just measured mine.
36" / 91.5cm to the male plug
20" 50cm to the female plug

Excellent advice! Thank you!

 

[ChrisOutdoors]

Ton of ways to charge something. You could also go the portable generator route.

1gal lasts 7 hours in some of them.

Amazon.com : A-iPower SUA2000iV Ultra-Quiet 2000-Watt Portable Inverter Generator CARB/EPA Compliant, 2000 Watt, RV Ready : Garden & Outdoor

Amazon.com : A-iPower SUA2000iV Ultra-Quiet 2000-Watt Portable Inverter Generator CARB/EPA Compliant, 2000 Watt, RV Ready : Garden & Outdoor

www.amazon.com

 

[GadgetGuy]

Ton of ways to charge something. You could also go the portable generator route.

1gal lasts 7 hours in some of them.

Amazon.com : A-iPower SUA2000iV Ultra-Quiet 2000-Watt Portable Inverter Generator CARB/EPA Compliant, 2000 Watt, RV Ready : Garden & Outdoor

Amazon.com : A-iPower SUA2000iV Ultra-Quiet 2000-Watt Portable Inverter Generator CARB/EPA Compliant, 2000 Watt, RV Ready : Garden & Outdoor

www.amazon.com

Too noisy for stealth flying nearby! That would draw way too much attention!
Generators are even more annoying than drones.
They'll come for the generator, and leave with the pilot!

 

[Trackerputnam]

I used wire bigger than the normal truck wiring just so there would be no voltage loss! Also, I charged all the batteries and phone and iPad just to see if truck batteries would drain down. No problem starting the truck.

 

[MAvic_South_Oz]

I'm convinced your recommendation is the solution to my problem, too, as mine seemed to stay on initially, after shutting the engine off, but stopped charging shortly thereafter. I've ordered the recommended step converter, and looking forward to charging while flying! Thank you!

Just wondering if you did go down the line of getting the step converter and making this up yet GG ?

 

[DanMan32]

Exactly! If that is the real problem (depends upon the vehicle), no step converter by itself will solve the problem. You'll need to rewire the cigarette lighter socket directly to the car battery, to bypass the ignition, so it is live when the ignition is off.

That, or you might be able to find a relay that only controls the outlet. Then with a couple diodes to prevent backfeed, you can energize the relay with ignition off.

 

[ChipDjipro]

Why not just buy enough batteries were you don’t need to charge them in your vehicle.

 

[DanMan32]

I used wire bigger than the normal truck wiring just so there would be no voltage loss! Also, I charged all the batteries and phone and iPad just to see if truck batteries would drain down. No problem starting the truck.

There will always be voltage loss. The amount of drop is dependent on wiring resistance and the current flowing through it. The stock charger draws 6.5A when it is actually charging. At that current, it only takes 0.15 ohms to drop 1v. The charger cutoff voltage is somewhere between 11.2-11.7v. The car battery output will drop rather quickly to 12v range when car is not running from the nominal 13v when alternator is running.

I have a Prius so having the car on draws little fuel, especially if I have the HVAC off. The only drawback is that I can't easily lock the car without me in it.

 

[Jeff A]

Many vehicles, especially North American ones, have the power shut off when the ignition is not engaged or not vehicle not running.

My experience is that an "American car" (What ever that is) has cigar lighters that are "Hot" all the time but imports are not. BTW, my Kia Sorento has 115v AC outlets in the back seat area. I have not used them but this may be a common SUV feature.

 

[MAvic_South_Oz]

Why not just buy enough batteries were you don’t need to charge them in your vehicle.

I guess it's a touring thing.
When we go 'outback' 4wd to inland desert regions of Australia, we are generally out for a week, longest trip without outlet power 5 weeks.
I generally use my 2nd AGM battery, in an Arkpak battery box, has live power to run fridge / freezer, recharge iphone/ pads etc.
I have 2.4 usb outlets all over the place as well as live HD 10a cigarette plugs in the rear of the cab, and rear canopy enclosed tub.

When I had 4 batteries on such a trip, I could easily fly almost continuously during a driving day, when stopping to fly say 10 mins here, 30 mins further another 10 - 15 min flight, etc etc.
Just bought another 2 new batteries, so could easily fly almost every 15 mins now I feel.
The car charger will charge up a fairly depleted battery in mabe 30 - 40 mins tops.

It just needs the reliable 13.1 + volts to work as it should, again, this is for my M1P car charger, but I imagine all DJI chargers would have the same needs (not the Spark 12v charger, it works on lower voltage fine).
This is ok if driving all day when charging, if stopped for lunch or to film another place, the step converter just ensures charging continues as voltage settles to normal 12.7v resting charge on the car battery.

 

[GadgetGuy]

Just wondering if you did go down the line of getting the step converter and making this up yet GG ?

Step converter arrived yesterday, so still acquiring the additional components to make it work. Still need the male and female car charging plugs and some heavy gauge wire to match the output wires of the step converter. Trip to an open auto parts store should do the trick. Sounds like an essential service trip to me!