Hi all,

I have a mavic pro battery[warrenty expired] that had not being used in nearly 2 months. Yesterday I checked it and it was completly dead. [no LEDs]
I plug it in to the charger for few hours but nothing happend then after reading few forum I decided to open the battery and charge it mannully using a lipo charger.

After struggling a lot I finnaly managed to unclip the cover and open the battey. Battery is showing 12v on the lipo terminals. So it can't be dead right?.

Then I decided to remove the balance wire and may be try to reset the intelligent board. I kept the balance wire disconnected for few hours and plugged it in nothing happened.

Then I unsoldered the ground wire and removed the balance wire, kept it for 1 hour and plugged it in ..

To my surprise LEDs came back on and it's now showing all four LEDs ON for 12v. Then I inserted the battery to the mavic and trued on the qaud. But no response from the mavic.

LED power on sequence is normal and it stays on. Then I checked the terminal using a multi-meter and there is no power in the terminals.   

Can anyone know how to solve this problem or direct me on right direction.

Big thank you for going through my lengthy explanation,
Chamika.

Hi there. Sorry for the unpleasant experience.
May I know if your battery can be charged now? If so, you can insert the battery back to the drone, and try to update by using DJI Assistant 2. You can reference the video of the operation of the update below:

If the battery still has errors, please kindly provide us with the photo showing the error.
Thank you in advance.

DJI Paladin Posted at 2018-2-9 02:51
Hi there. Sorry for the unpleasant experience.
May I know if your battery can be charged now? If so, you can insert the battery back to the drone, and try to update by using DJI Assistant 2. You can reference the video of the operation of the update below:
https://www.youtube.com/watch?v=HZE-fP28htI

Hi Thank you for the reply.

No the DJI charger wont charge it. When I plug the battery to charger LED sequence blink few times and it turn off. I'll send a video ASAP.

Thank you.

Hi have the same issue bought 6 batteries in the states and assume they were standing to long now no lights switch on opened one and have 11.9 v removed balance leads now lights up but doesn't charge or supply power to drone

Hello,
I have a same issue!
When I received my pack the batteries in fly more combo pack were dead. I opened them and measured the voltage accross the battery.
One was around 12 volts one was 2.5 volts.
After manually charging and disconnecting/connecting balance plug now both of them showing charged on the LEDs but no voltage at the output connector terminals! And no charging on this terminal either.
The drone cannot be operated by these batteries either.
Is it a firmware issue? How can I enable the output connector to supply the batteries’ voltage or to be able to charge by the DJI’s stock charger?
P.S.: I cannot use DJI warranty.
Please help me on this issue!
Thanks in advance,

I do not think this is firmware related. And it is really not worth struggling with batteries like this and risking your drone crash or even damage of some other property or person due to drone crash.

Being an electronics engineer I dont think this is such a risky situation. Battery inside the box is brand new and no flaw even with the cells. The only thing is the control circuit does not switch the battery output to the main connector for some reason. To repair this situation if possible should not increase the overall flight risks due to battery, should it?

Any support from DJI support team please? I can facilitate the environment for firmware update even from the JTAG interface of MSP430 if applicable.
Thanks,

djiuser_b47c9WN5QIMr Posted at 5-25 02:30
Any support from DJI support team please? I can facilitate the environment for firmware update even from the JTAG interface of MSP430 if applicable.
Thanks,

Or disconnecting balance connector together with battery main positive pole (red cable) and waiting for long enough to let the data that prevent the battery from both start charging or providing power to the aircraft, to be erased. You can pm me if there is such kind of solutions to this issue. I can try.
Thanks,

has anyone figured this out yet

any update please thenks

hi
any update please

i have several battery wiyh same problem
i open them
try so many things

nothing works
still did not take a charge or power up the drone
and all the cell are 100% balance and working

thanks
yossi

must be a way to update firmware or reset the pcb of the battery without the drone

Hi, I have the same Problem. I even probed all the ICs on the board and it seems that the main IC wont turn the second stage of transistors/mosfets on. So it looks like a battery software problem.

Darkside447 Posted at 2-5 05:05
Hi, I have the same Problem. I even probed all the ICs on the board and it seems that the main IC wont turn the second stage of transistors/mosfets on. So it looks like a battery software problem.

Hello, yes is software issue. I can reprogram it. I'm in Brazil. Look at this advertising:

https://suporte-tecnico.mercadolivre.com.br/MLB-1418863700-manutenco-reparo-linha-bateria-dji-phantom-3-4-mavic-ronin-_JM

I have been fixed dozens of it.

I have 3 of these. I suspect the BQ30Z55 chip disabled the battery due to deep discharge (mine were circa 1V per cell when I re-charged them).
https://github.com/o-gs/dji-firmware-tools/wiki/WM220-Battery-Intelligent-Board

If it's the case, then the flags can be lifted using TI evaluation software and TI EV2300 programmer.

Yes , as soon as you disconnect the positive the battery software reverts back to default safe mode , wont give out any voltage , hope there is a  more cost effective bypass though , those interface programmers are around a 100 dollars .  

If you're facing an issue with your Mavic Pro battery firmware where the LEDs are on but there's no power, try the following steps:  Disconnect Battery: Remove the battery from the Mavic Pro. Inspect Connections: Check for any visible damage or debris on the battery and drone connectors. Reconnect Battery: Reconnect the battery securely. Hard Reset: Press and hold the power button on the battery for about 10 seconds, then release. Update Firmware: Ensure that both the Mavic Pro and the battery firmware are up to date using the DJI Assistant 2 software. If the issue persists, consider contacting DJI support for further assistance or consider professional repair services.

https://fixissuenow.com/dji-mavic-pro-battery-reset/