Anything to worry about (battery)
1462 22 2017-8-28
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Flybee
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I checked the battery and found a small deviation, is this something to worry about?

Is there a way to "correct" it?


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2017-8-28
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Tombolian
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Don't know of a way to fix this, I think it's just the difference between various cells... According to this resource, as long as an individual cell doesn't go below 3V, you shouldn't have much to worry about.  So the question becomes "how low is the lowest cell when you consider your battery 'depleted'"?
2017-8-28
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mpaka
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Try depleting your battery to 8%.  Fly it very low till 11% and land. While on the ground leave it on until it hits 7-8%. Cool it down room temp and charge to full. Maybe it will help. You should do this every 20 cycles.
I think it is also recommended by DJI.
2017-8-28
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Flybee
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mpaka Posted at 2017-8-28 10:51
Try depleting your battery to 8%.  Fly it very low till 11% and land. While on the ground leave it on until it hits 7-8%. Cool it down room temp and charge to full. Maybe it will help. You should do this every 20 cycles.
I think it is also recommended by DJI.

Thank you very much for the input, will try that.

Happy flying
2017-8-28
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Flybee
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Tombolian Posted at 2017-8-28 09:51
Don't know of a way to fix this, I think it's just the difference between various cells... According to this resource, as long as an individual cell doesn't go below 3V, you shouldn't have much to worry about.  So the question becomes "how low is the lowest cell when you consider your battery 'depleted'"?

I have to check that figure to see more in detail.

thank you for your response

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2017-8-28
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george_007
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The cells in the battery are all charged individually. A full charge should solve the problem. If not you may have a faulty cell.
Small deviation is to be expected in some batteries and is nothing to worry about.

Depleting your battery will not solve the problem and may actually damage all cells.
Deep discharge is never good for Lithium batteries.
2017-8-28
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DJI Diana
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According to the pic, the voltages of the cells are normal, the deviation is in the normal range. No worries.
2017-8-28
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Flybee
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george_007 Posted at 2017-8-28 15:00
The cells in the battery are all charged individually. A full charge should solve the problem. If not you may have a faulty cell.
Small deviation is to be expected in some batteries and is nothing to worry about.

Thank you very much george_007

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2017-8-28
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Flybee
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DJI Diana Posted at 2017-8-28 20:03
According to the pic, the voltages of the cells are normal, the deviation is in the normal range. No worries.

Thank you DJI Diana, then I just keep on having fun.
2017-8-28
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The Rev
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Your Mavic will detect battery problems and wont take off if it detects a faulty cell as I have this problem at the moment and they are only under warranty for 6 month and mine is just over that
2017-8-28
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ImHereToCrash
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no reason to need to correct it if it is 0.10 Volts deviation or below...  if you wish to "reset" it you can hover it until it dies keep it from landing until no power.. not till it says 0% but rather until aircraft shuts off completely from no power from batteries..  then plug it into the charger (alone no other batteries) let it charge until it finished..    no guarantee it will completely self balance back to perfectly matching....  but atleast the power cycling will reset the power management in the battery and it recalibrate each end stop of power better..  
2017-8-28
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DJI Diana
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Flybee Posted at 2017-8-28 20:46
Thank you DJI Diana, then I just keep on having fun.

Yes, hope you can enjoy it, happy flying.
2017-8-29
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$gambino$
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I domt recommend running battery that low ever u should stick to the 20% rule. Lipos do not last long when run that far down. Older dji batteries used to reset at like 11 or 8% but i never did that. I fly helis and if i did that once or twice I would definitely be able to tell a difference in performance sometimes cells cant recover from veing discharged to much there is two rules to follow never discharge below 20% so the 80/20 rules (put back 80%) and always let batteries cool after using. Heat is anotger killer of lipo batteries. Op your minor deviation is ok. Fully charge it and the balancing part of the charger should take care of that
2017-8-29
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$gambino$
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I do wonder why u only have 3680 mah total capacity??? Stock is 3830mah....my 2 batterys are 3914 and 3975.... Maybe some batteries have slightly more mah and some have slightly less???
2017-8-29
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mpaka
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george_007 Posted at 2017-8-28 15:00
The cells in the battery are all charged individually. A full charge should solve the problem. If not you may have a faulty cell.
Small deviation is to be expected in some batteries and is nothing to worry about.

When you deplete DJI smart batteries to 8% they are around 3.50v per cell, which is faaar from damaging it.  You will damage LIPO battery if you go under 3.30v per cell which is impossible with DJI battery, except
if you maybe leave it on in AC and go away from it all night...

I also had deviations with new batteries, but never more than 0.2-0.3 between cells.
Recently one of mine P3P batteries died during flight (didnt fell just had OSD warning). Warning stated that one cell is damaged... And it really differs in voltage from other 3 cells.

On my C2 quick button i always keep battery info and check voltages, especially if i need to fly harder or fly during cold winter.

So do not worry about damaging battery if you go 7-8%, you are very safe there. Google LIPO batteries and see where damage occurs for 4S batteries it is under 3.30v and even lower than that.
2017-8-29
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Sportbike_Pilot
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Good to know. Wow 20 cycles on this battery already. How many cycles can these batteries sustained and still be functional ?
2017-8-29
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george_007
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Flybee Posted at 2017-8-28 20:46
Thank you very much george_007

Happy flying

I feel obligated to add some info.

My previous comment is correct and valid for the cells in the battery.

However, there is also a "smart" part in the DJI batteries, the electronics
and programming inside the battery casing in place to protect the cells
from unnecessary abuse and provide you with information.

With the "smart" part of the battery in focus it could make sense to deplete the
battery pack since that will trigger the calibration of the battery. So basically I would
say that doing that is still (somewhat) bad for the battery cells but it will calibate your "sensors"
meaning if they are off they will after a full dicharge and charge show correct values.

So doing a full discharge every now and then is ok. It will not damage the cells too much
but it will also not do any good for the cells, only the "sensors" that provide you with information
about the battery. Which of course is also what the Mavic read and acts upon so proper calibration
is important from other perspectives.

As others have already stated I would not worry about the small difference you see in voltage
between your cells. It's not worth a full discharge to correct it but it's still ok to do it if you want to.

Just don't fully discharge your batteries too often, like more than once a month.
I would say maximum once a month.
2017-8-29
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Flybee
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$gambino$ Posted at 2017-8-29 02:49
I domt recommend running battery that low ever u should stick to the 20% rule. Lipos do not last long when run that far down. Older dji batteries used to reset at like 11 or 8% but i never did that. I fly helis and if i did that once or twice I would definitely be able to tell a difference in performance sometimes cells cant recover from veing discharged to much there is two rules to follow never discharge below 20% so the 80/20 rules (put back 80%) and always let batteries cool after using. Heat is anotger killer of lipo batteries. Op your minor deviation is ok. Fully charge it and the balancing part of the charger should take care of that

Thank you very much for your valuable input.

Happy flying
2017-8-29
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Flybee
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$gambino$ Posted at 2017-8-29 02:56
I do wonder why u only have 3680 mah total capacity??? Stock is 3830mah....my 2 batterys are 3914 and 3975.... Maybe some batteries have slightly more mah and some have slightly less???

I have never thought about these figures, two of my batteries are from 2016 and one from 2017, have to check if there is any difference
2017-8-29
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Flybee
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Sportbike_Pilot Posted at 2017-8-29 04:06
Good to know. Wow 20 cycles on this battery already. How many cycles can these batteries sustained and still be functional ?

This battery is from 2016 (Manufactured) delivered in Jan 2017 so I don't think it's that much actually. I have heard some figure about 200 times but can't remember from where
2017-8-29
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Flybee
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george_007 Posted at 2017-8-29 07:34
I feel obligated to add some info.

My previous comment is correct and valid for the cells in the battery.

thank you once again
2017-8-29
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mpaka
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Running your battery to 8% (3.50V) will not damage your battery, LIPO batteries take damage if they go under under 3.00V per cell.

Just search for it, its all over the internet...
2017-8-30
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george_007
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mpaka Posted at 2017-8-30 01:31
Running your battery to 8% (3.50V) will not damage your battery, LIPO batteries take damage if they go under under 3.00V per cell.

Just search for it, its all over the internet...

There is not a sharp voltage limit where the battery suddenly takes damage. The deeper you discharge the battery each time, the fewer cycles you will get from the battery.

This is also on the Internet. :-)
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2017-8-30
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