Hello,

Is it still possible to use this battery? It was only charged 9 times (!), always with original DJI charger. And now it shows a cell with different voltage (the one on the right, on this attached pic):

4,19V 4,18V 4,28V

What can I do?

Thank you

The only advice I have seen around this is to discharge as low as possible then recharge.  How old is the battery as the DJI warranty for batteries is only six months.

Anthony566 Posted at 2018-1-5 09:29
The only advice I have seen around this is to discharge as low as possible then recharge.  How old is the battery as the DJI warranty for batteries is only six months.

Thank you. It's not even 4 months old

It may just be a calibration issue as anthony566 mentioned.
To be reasonably certain it is a temporary issue, i would fully charge and then run the drone without blades, until the 10% warning. This is where if it was flying, it would land itself. Then i would recharge after the battery had cooled off. See if the voltages are withing an acceptable range. Perhaps another run and recharge cycle for luck. If ok, do some low altitude flights and practice different flight techniques to see how the drone behaves. To start the drone, just bring the sticks down and together. Just leave it to run and dont try to rev up. If you do it will show an error and stop. Good luck.

fans9553217f Posted at 2018-1-5 09:41
It may just be a calibration issue as anthony566 mentioned.
To be reasonably certain it is a temporary issue, i would fully charge and then run the drone without blades, until the 10% warning. This is where if it was flying, it would land itself. Then i would recharge after the battery had cooled off. See if the voltages are withing an acceptable range. Perhaps another run and recharge cycle for luck. If ok, do some low altitude flights and practice different flight techniques to see how the drone behaves. To start the drone, just bring the sticks down and together. Just leave it to run and dont try to rev up. If you do it will show an error and stop. Good luck.

Thank you for your advice! I'll try that

according to DJI, 0.10 V is within specs., but I would let it discharge to 5-10% and then recharge it, for 30-60 minutes beyond 100% charge per flashing green lights. then test it again

Locoman Posted at 2018-1-5 10:20
according to DJI, 0.10 V is within specs., but I would let it discharge to 5-10% and then recharge it, for 30-60 minutes beyond 100% charge per flashing green lights. then test it again

Ok, thank you

If I'm not mistaken, the app will warn you if there is a SIGNIFICANT deviation in cell voltages.  There will be some deviation normally although the smart battery attempts to do some load balancing between cells.  If you do longer (time-wise) and more rigorous flights, you may find better balance.  

Griffith Posted at 2018-1-5 11:43
If I'm not mistaken, the app will warn you if there is a SIGNIFICANT deviation in cell voltages.  There will be some deviation normally although the smart battery attempts to do some load balancing between cells.  If you do longer (time-wise) and more rigorous flights, you may find better balance.

Yes, the app would probably tell me if it would be worst. But I just prefer to be sure, I don't want my little bird to crash because of a bad battery ;)
Thank you

same problem for me, the only advise from a DJI Administrators was discharge to 0% than recharge to 100% ...use the battery to discharge again....but nothings happend and DjiGo tells me battery broken/defect...after 24 charges...now i use that battery only to charge a phone (power bank)...but 24 charger for 100Euro? ...after 7 mounts....

djiuser_LdOBUgD Posted at 2018-1-5 11:50
Yes, the app would probably tell me if it would be worst. But I just prefer to be sure, I don't want my little bird to crash because of a bad battery ;)
Thank you

I'd agree with a previous post regarding discharging the battery.  Set critical battery level to about 10% and let it hover at 4-5 feet until critical battery invokes a forced landing.  Can't remember if it attempts RTH, but I'd be sure the RTH height is as low as possible.

Griffith Posted at 2018-1-5 12:18
I'd agree with a previous post regarding discharging the battery.  Set critical battery level to about 10% and let it hover at 4-5 feet until critical battery invokes a forced landing.  Can't remember if it attempts RTH, but I'd be sure the RTH height is as low as possible.

Hey guys,

I couldn't discharge the battery lower than 6%. Just now, the Mavic shut down, with 6% battery left... Is that normal?

djiuser_LdOBUgD Posted at 2018-1-5 13:09
Hey guys,

I couldn't discharge the battery lower than 6%. Just now, the Mavic shut down, with 6% battery left... Is that normal?

Yeah that's about right.

djiuser_LdOBUgD Posted at 2018-1-5 13:09
Hey guys,

I couldn't discharge the battery lower than 6%. Just now, the Mavic shut down, with 6% battery left... Is that normal?

No - do you have the DJI battery power bank adaptor? Discharge using that by charging an iPhone/device. Get it as close to 0% as possible. Then recharge to 100% after it has cooled down. If the voltage varies by more than 0.8V after that then send it back if only 4 months old (providing you also have <200 charge cycles).

djiuser_LdOBUgD Posted at 2018-1-5 13:09
Hey guys,

I couldn't discharge the battery lower than 6%. Just now, the Mavic shut down, with 6% battery left... Is that normal?

That'll be fine

A CW Posted at 2018-1-5 14:00
No - do you have the DJI battery power bank adaptor? Discharge using that by charging an iPhone/device. Get it as close to 0% as possible. Then recharge to 100% after it has cooled down. If the voltage varies by more than 0.8V after that then send it back if only 4 months old (providing you also have

Ok, I'll do that. Thanks

A CW Posted at 2018-1-5 14:00
No - do you have the DJI battery power bank adaptor? Discharge using that by charging an iPhone/device. Get it as close to 0% as possible. Then recharge to 100% after it has cooled down. If the voltage varies by more than 0.8V after that then send it back if only 4 months old (providing you also have

Ok, I tried to do it: doesn't work. No more power comes from the battery. I can't charge anything with it anymore

djiuser_LdOBUgD Posted at 2018-1-5 14:25
Ok, I tried to do it: doesn't work. No more power comes from the battery. I can't charge anything with it anymore

Have you now tried to recharge it?
Generally when this happens to a lipo pack it is because one of the cells gets a higher ESR (equivalent series resistance). Then what happens during charge, this cell gets overcharged and during discharge this cell gets overdischarged. It woudl have ben good if you were able to see what the voltage of the cells were when it got down to 6%.

DJI need to make a really smart battery back that can detect a cell failure and activate an emergency power supply that is powered from the remaining 2 good cells, boosting the voltage, so the craft can still return home or land without falling from the sky..

Mavdude Posted at 2018-1-5 14:37
Have you now tried to recharge it?
Generally when this happens to a lipo pack it is because one of the cells gets a higher ESR (equivalent series resistance). Then what happens during charge, this cell gets overcharged and during discharge this cell gets overdischarged. It woudl have ben good if you were able to see what the voltage of the cells were when it got down to 6%.

I wanted to check the voltage around 5%, but I wasn't fast enough, because it shut down at 6%! ;)

Anyway, tomorrow I'll charge it and see what happens.
Thanks for your answer

You're on the right track.  Until you have run a few "long" cycles, the calibration is likely to be off a bit.  Discharging it to a low value (never zero) and then recharging it FULLY (until all lights turn off, not just until the last one lights) should rebalance the sensors in the smart part of the battery.  When you use that battery after that, be aware that it once gave a problem and keep an eye on it as you use it to see if you have cured it.  The more cycles you put on it, the more balanced and trustworthy I would consider it unless it tells you otherwise.

djiuser_LdOBUgD Posted at 2018-1-5 14:42
I wanted to check the voltage around 5%, but I wasn't fast enough, because it shut down at 6%! ;)

Anyway, tomorrow I'll charge it and see what happens.

When you do recharge it, keep a close eye on it, perhaps let it get to about 50% and put it in the drone and check the cell voltages. If that end cell is still higher, try not to let it exceed 4.3v as this could damage the cell.

Ok - stop on 6% and fully recharge then turn it all back on and see how that’s affected the cell voltage. If still out repeat the process or box it up and get a ticket from DJI support to ship it back for a brand new replacement. I wouldn’t fly with it if the variance is too big or any errors pop up - an £85 battery isn’t worth an £850 drone...

A CW Posted at 2018-1-5 15:35
Ok - stop on 6% and fully recharge then turn it all back on and see how that’s affected the cell voltage. If still out repeat the process or box it up and get a ticket from DJI support to ship it back for a brand new replacement. I wouldn’t fly with it if the variance is too big or any errors pop up - an £85 battery isn’t worth an £850 drone...

Ok guys! I completely discharged and recharged it. This morning I used it and let it discharged till the drone automatically landed (10% battery left).

It seems that the "bad" cell is getting better again!

Cool - couple more cycles and it should be OK.

Griffith Posted at 2018-1-5 11:43
If I'm not mistaken, the app will warn you if there is a SIGNIFICANT deviation in cell voltages.  There will be some deviation normally although the smart battery attempts to do some load balancing between cells.  If you do longer (time-wise) and more rigorous flights, you may find better balance.

It will warn you, but then you could get an immediate power loss, which is not good when you up in the air.
Always better to stop using a battery with a signifcant voltage difference, claim a warranty rather than trying to save it.

Agreed, but I don't think a couple tenths V is abnormal.

djiuser_LdOBUgD Posted at 2018-1-5 13:09
Hey guys,

I couldn't discharge the battery lower than 6%. Just now, the Mavic shut down, with 6% battery left... Is that normal?

That's about right.  The smarts in the battery will not allow it to discharge completely.  The percentage shown is calculated, but to my knowledge, the actual calculation is not divulged.  It could be as simple as a  % of battery voltage between full charge and critical voltage, or some linearized version of that. If you've ever noticed the relation between flying time and battery drop, you;ve probably noticed that flying time falls off quickly below about 30% battery.

Griffith Posted at 2018-1-8 05:52
That's about right.  The smarts in the battery will not allow it to discharge completely.  The percentage shown is calculated, but to my knowledge, the actual calculation is not divulged.  It could be as simple as a  % of battery voltage between full charge and critical voltage, or some linearized version of that. If you've ever noticed the relation between flying time and battery drop, you;ve probably noticed that flying time falls off quickly below about 30% battery.

Ok, after several discharged and charged again, it finally got worst (the gap between the different voltage of the 3 cells), so I contacted DJI and they told me to send it to them for a repair...
A repair of the battery? Let's see...

I have 3 mavic batts like this and all on number 3 cell 20 cycles each , mine are  0.100 lower rather than high like the original poster ,
I have looked after mine landing at 30% , tried the discharge to switch off using the usb adaptor with no luck , mine are all out of warranty , I just find it strange that it is cell 3
on each battery going out of whack , any one else noticing a problem with the third cell ?

djiuser_LdOBUgD Posted at 2018-1-11 09:01
Ok, after several discharged and charged again, it finally got worst (the gap between the different voltage of the 3 cells), so I contacted DJI and they told me to send it to them for a repair...
A repair of the battery? Let's see...

Smart move.

UPDATE

Hello everybody,

DJI said they will repair my battery. Finally, they just sent me a new one

RENSMUSIC Posted at 2018-1-22 13:14
UPDATE

Hello everybody,

Great!!!