Air 2 / Air 2S USB charging redux

[Elthree]

One of the things I appreciate with my Mini 2 setup is I have it set up to recharge batteries in the field from USB PD-equipped (45W & 60W) powerbanks (including when away from a vehicle). It actually recharges multiple batteries in a reasonable timeframe (and I have 2x Mini2 and 2x Mini1 batteries in the kit) so I can work most of a day (with some breaks which are going to happen anyway).
Obviously the Air 2 family's lack of USB-charging options is an issue. But with 3x batteries maybe just one USB charger will give enough flexibility (and the Mini 2 hiding in the backpack too to give a backup). So I've been looking at options:

This "QC3.0" charger (under various brand names) has been mentioned here previously.

Mavic Air 2 Battery Charger QC 3.0 USB Battery Charging Hub Compatible with DJI Mavic Air 2 and Air 2S : Amazon.com.au: Electronics

Mavic Air 2 Battery Charger QC 3.0 USB Battery Charging Hub Compatible with DJI Mavic Air 2 and Air 2S : Amazon.com.au: Electronics

www.amazon.com.au

The need to connect up two USB ports to accelerate the charging below 2 hours is disappointing. But it's better than nothing.

I've also seen this supposedly-PD-capable charger:

Gootu Mavic Air 2 and Mavic Air 2S Charger, Supports up to PD 100W bidirectional Fast Charge，Suitable for DJI/DaJiang Drone Mavic AIR 2, Mavic AIR 2S Battery Charging, Drone Mavic Accessories.(Black : Amazon.com.au: Toys & Games

Gootu Mavic Air 2 and Mavic Air 2S Charger, Supports up to PD 100W bidirectional Fast Charge，Suitable for DJI/DaJiang Drone Mavic AIR 2, Mavic AIR 2S Battery Charging, Drone Mavic Accessories.(Black : Amazon.com.au: Toys & Games

www.amazon.com.au

The single-port 38W charging is appealing, but the price seems a little on the silly side.

If that charger or something similar turned out to be reliable, the only other thing I might wish for would be the ability to connect it to the multi-charging hub to charge batteries in sequence, but that's not a killer feature.

Does anyone have recent experience with Air 2S battery charging to comment?

 

[Capt KO]

Did your A2 come with a (cig lighter type) car charger? If so, a motorcycle battery with a male accessory plug will do the job in the field. I do that but with a car battery, ac/dc inverter and 110v multi-charger. Use it for charging fishing drones, cameras, and phones, at the beach. Pile it all in a beach wagon with rod holders, cooler, and beer.
PS, some beaches don’t allow alcohol (lesson learned)

 

[Elthree]

One of my powerbanks has AC output, so that's an option. But a lot clunkier to carry in the backpack (and possibly less efficient). And that one's the (physically) bigger powerbank which usually stays at base as backup.
It would be so much nicer for things to run off USB-C like all my other devices.

 

[kevinkga]

It seems so obvious to allow MA2/2S to charge via USB-C. Most of the newer variants have this feature too, like the Mavic 3/Mini 3 series.

So I decided to make my own!

My hack is to modify an existing Car DC Charger based on the following: WANGCL Drone Car Charger 3 in 1 Intelligent Charger Hub Drone Battery Remote Control Charging for DJI Mavic Air 2 Air 2S: Amazon.co.uk: Electronics & Photo
The above was chosen for a few reasons:

• Cheap-ish: ~£35
• Good ratings: I've used it as my main car charger for a while now and it works just great
• Wide VDC input: 12-16v

So I opened up the charger and it looked like I had everything I needed nicely laid out! The only 2 things I need to modify are:

• The dangling red and black wires to be attached to a DC Barrel connector (2.5mm)
• I would need a new housing for the modification

I have open-sourced a design for the case here: Onshape



At this point you're probably asking yourself how on earth does this involve USB-C? Well I typically have a 136W PD GaN charger (https://www.amazon.co.uk/LinkOn-Charger-Portable-International-Replacement-Black-136W/dp/B0856PBJPZ). I use this tiny device as a single charger for:

• Laptop: Macbook Air M2 (for fast charging)
• Headphones: Bose 700
• Phone: Samsung S22
• Portable Projector: Nebula Capsule 3
• Drone: Now possibly the Mavic Air 2!!

The GaN charger can easily provide 15vdc at around 10A+ so all that I need to do now is wait for the delivery of my eMarket USB cable to Barrel connector (https://www.amazon.co.uk/gp/product/B0BHQNZJ6B) and that will plug into the modded car charger.

The advantage of using a barrel socket is that I can charger it from a wall, using the USB GaN Charger when stationary and use a cigarette lighter cable (e.g. https://www.amazon.co.uk/Cigarette-Lighter-Adapter-Extension-Monitors/dp/B07JXZDLHL) for when I'm in the car. This solution should help me get rid of bulk and weight of carrying around a pointless power brick for AC charging and an additional brick for car charging. So far the design (if it all works as expected) looks pretty compact, specially compared to what's already out there and supports dual parallel battery charging.

Initially, I thought that the power supply was just a dumb DC Power supply that supplies a fixed 13.2v output but I wasn't sure. If someone can confirm this then I would probably be able to make a more compact design using a stepdown converter. If anyone knows more about this please let me know!

I'll post more updates here as this project progresses.

Please let me know if you guys have additional ideas.

 

[Elthree]

If that's connected to a USB-C supply, it will have to do enough of the PD protocol to negotiate the voltage it wants instead of the default 5V.

In the end I simply bought myself one of these:

https://www.amazon.com/dp/B094JB3C8G

Small, compact, and neat. It will at least charge one of the cells from a powerbank while I fly on another.

 

[kevinkga]

If that's connected to a USB-C supply, it will have to do enough of the PD protocol to negotiate the voltage it wants instead of the default 5V.

In the end I simply bought myself one of these:

https://www.amazon.com/dp/B094JB3C8G

Small, compact, and neat. It will at least charge one of the cells from a powerbank while I fly on another.

Yes indeed. I ended up swapping the cable for a fixed emarked one that will negotiate with the PD for 15v at 3 amps. So that becomes 45w of parallel charging effectively. Here's the actual cable i used: DSD TECH MagicConn SH-CP15A USB... https://www.amazon.co.uk/dp/B0B9FTJHGV

 

[kevinkga]

So I ended up getting an emark cable that would support 5A @ 15v, to be on the safe side. Here's a video update of the progress on the project so far: