Mavic air Battery

John32 · May 3, 2020

See this

Detritalgeo · May 3, 2020

The Phantom 2 is older technology so it may have worked then. I have worked on P4, Mavic Pro and Mavic Air batteries and the electronics disable charging if voltage is too low. People are welcome to try the reset but it won't work unless you have the software to reset the error flag in battery management system circuitry. This software exists but is not cheap.

Keithg1 · May 4, 2020

Thanks Detrilago and everybody else who offered advice. Hacking the firmware is beyond the scope of my capabilities, especially on a chip of that tiny size so I guess that 3 x new batteries are required and, in future, I'll charge up once every 2 months!
But because the batteries are useless unless fixed, I'll carefully try manually charging each of the 3 cells individually up to 3.4v and see what transpires. Nothing to lose!

Jerra · May 8, 2020

Detritalgeo said:
The cell at 0V is most likely damaged internally, it is very odd for a normal healthy cell to be completely dead. Either way, if you are able to revive it, it will keep misbehaving and may not be worth trusting in your drone.

If you have an interest in the batteries, you could invest in a nice hobby charger such as the SKY-RC B6 (iMAX B6 V2 Changer), it is a nice unit. Li-ion must be charged in a CC-CV method, this means constant current-constant voltage. Most Li-ion cells muct not me charged above 4.2V but some high-voltage cells are designed to reach 4.35V.

You must be very careful with Li-ion / Li-Polymer cells to avoid fires, take a look around Second Life Storage for some general info. It is a community of hobbyists that dismantle old laptop Li-ion batteries, test the cells and recombine to form new battery packs.

The battery management electronics of the Mavic Air battery is controlled by the BQ9003 IC by Texas Instruments but there is not much info about it online.

This looks what I need, amazing. I looked at the spec sheet but the charger attachment for the Mavic is not supplied, and it’s not a prescribed accessory, which is a swizz as it shows it on the website, charging a Mavic battery.

Do you know what connector the charger needs for the Mavic? I was going to look for one on Amazon.

Thanks

Detritalgeo · May 8, 2020

Jerra said:
This looks what I need, amazing. I looked at the spec sheet but the charger attachment for the Mavic is not supplied, and it’s not a prescribed accessory, which is a swizz as it shows it on the website, charging a Mavic battery.

Do you know what connector the charger needs for the Mavic? I was going to look for one on Amazon.

Thanks

I just searched 'Mavic Air charge cable' on AliExpress..amazon must have something too..but just remember this wont work if the chip is locked.

US $3.07 |Adapter Charging Cable Line Balance Converting Fast Transfer Plug Drone Accessories Fast Charging line For DJI Mavic Air|Drone Cables| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

Keithg1 · May 8, 2020

I have opened up the other 2 dud-batteries and they all read approximately the same as the first as posted earlier above:

Cell 1: 3.7 v
Cell 2: 1.9v
Cell 3: 0.01v

Detritalgeo · May 9, 2020

Seems like a defective batch if that's the case. If only this was caught when in warranty coverage.

Keithg1 · May 9, 2020

Yes! It could be so as the only remaining, working battery is one purchased about 6 months after purchasing the original MA package with 3 batteries.

Ynksfan27 · May 9, 2020

Jerry A said:
Well !! what are you going to do about it? Send me a Box I can use to return them, and then send me Four That Will Charge. My Turtle Ride starts soon and I want to get some video.
I sent you a photo of how I have them hooked up, and they are hooked up correctly.My Group that uses Drones will look somewhere else If you do not do the right thing.

What the heck are you even talking about? Seems to be your problem and nobody else’s on here?

Jerra · May 17, 2020

Detritalgeo said:
I just searched 'Mavic Air charge cable' on AliExpress..amazon must have something too..but just remember this wont work if the chip is locked.

US $3.07 |Adapter Charging Cable Line Balance Converting Fast Transfer Plug Drone Accessories Fast Charging line For DJI Mavic Air|Drone Cables| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

Chip locked?

Oh dear. I didn’t know about this? I thought they would just be ‘hibernating’ as DJI called it?

What, May I ask, causes the chip to lock, and can this be rectified?

Detritalgeo · May 17, 2020

It is part of the battery management system. The battery has a small chip that monitors the voltage of each cell, the charge/discharge current, temperature, etc.. This chip also controls when the battery will be shut down (if you run the drone to nothing).

In addition to all of these parameters the chip also monitors for flags that disable the battery. One of these flags is if any cell drops below a specified voltage that is deemed to cause damage to Li-ion cells or may indicate an issue with the cell. This flag will cause the charging circuitry to be disabled as a precaution.

If you have the right software and are able to hack-into the data lines for the IC you can reset this flag in a similar fashion to that shown in the video above. This is a fairly technical task and would require some time and investigation.