Hey folks. I wanted a way to charge my aircraft's batteries while out in the field - and without going to my car.  This setup would be awesome for a safari or a camping trip - off the grid and away from power.  Here are some pics from the project.


The original charger. Allows you to send 12V power to the DJI 3-bay charging dock. Matching DJI's specs, the voltage is converted to 13.05V (and just under 4A of current).





The original car charger without its cover.

I ordered an appropriately sized junction box from Amazon.

I decided to use a 5.5mm x 2.1mm female plug (to connect from either of 2 power sources). I used 18AWG wire to match the original input wire guage. This is important - 20AWG could get hot, or trip the fuse - at worst, 20AWG cause a fire - we're talking up to 10 amps here (from a car battery in one of the set-ups)!  If you're interested in doing a similar project, check your wire ratings! Most of the stuff available amazon is 20 or even 22AWG - not appropriate for this much current!

Some butt slices to marry the female end to the original. These are the only parts that did not come from Amazon (did not need 100 of them, so I went to Home Depot).

With the new female connector in place, I measured and drilled 3 holes in the junction box - input, output, and LED. Everything fits so nicely

I sealed it all up, and gave it a go. The power pack is connected to the converter via a male-to-male 5.5mm x 2.1mm 18 gauge wire. The observant electronics geek will also notice a 2.1mm female to 2.5mm male adapter (going into the power bank). I got the cable and adapter from Amazon, of course

   And it works!

The math? I thought you'd never ask

  DJI's charging bay expects 13.05V at 3.83A = 50Watts. My power bank is capable of supplying 12V at a maximum of 4.5A. That's 54 watts! (made it with 4 amps to spare). So the converter is getting plenty of current with this set up. She can handle it - recall that the car adapter draws at 12Vx10A= 120W. Steps up voltage, and steps down current.

H

ere's the other set up. Same converter, but married to a 12V DC adapter - ready for charging in my car. Again, the 5.5mm x 2.1mm female adapter is the key. She can get power from my power bank ot a car charger.

Before and after. A simple car charger that now can double as a remote field charger!  

Thank you for reaching DJI forum. Just a friendly reminder, we don't recommend any modification or self repair. We are unable to ensure the performance and compatibility. Thanks for your understanding.

thats an awesome mod for portability. What power bank you have that outputs 12v?

DJI Paladin Posted at 2018-9-21 07:50
Thank you for reaching DJI forum. Just a friendly reminder, we don't recommend any modification or self repair. We are unable to ensure the performance and compatibility. Thanks for your understanding.

Understood. Just to be clear, I did not (and would not) modify any DJI products or components. The 3bay charging dock is stock, and will remain so. I simply provided a different source for electron transportation

Rotaryknight Posted at 2018-9-21 10:12
thats an awesome mod for portability. What power bank you have that outputs 12v?

It’s the Gissaral 35,000mAh power pack. The most important factor in whatever power source you choose is to ensure that at least 50 watts gets  to the converter.
If you, for example, send 12V at 4A, that’s only 48Watts. Getting to 50 (which is what the DJI dock expects) would violate the laws of physics it may also damage the bay.

I would also not recommend going over 120W from any source (into the converter that is). The aftermarket converter expects 12v at a max of 10amps. Don’t push it beyond specs.

LuckiePilot Posted at 2018-9-21 10:24
Understood. Just to be clear, I did not (and would not) modify any DJI products or components. The 3bay charging dock is stock, and will remain so. I simply provided a different source for electron transportation

Alright. Please let us know if you have other concern, we're here to help. Enjoy and always have a safe flight.

Great thread - thanks for sharing   

Nice work.