thelittledrone Posted at 5-26 04:44
Hi folks,

Is 0.125V should be consider as a strong cell deviation? ( M2P battery, only 15 charging cycle)

Yes, it's large, but it's not necessarily the end of the world.  If you would post your log onto phantomhelp and post the link back here, somebody can give you a better answer.  

https://www.phantomhelp.com/LogViewer/Upload/#

Mark The Droner Posted at 5-26 14:52
Yes, it's large, but it's not necessarily the end of the world.  If you would post your log onto phantomhelp and post the link back here, somebody can give you a better answer.  

https://www.phantomhelp.com/LogViewer/Upload/#

Thanks,
here it is :
https://www.phantomhelp.com/LogViewer/8JLY5CUK3VFO42EBPS22/

thelittledrone Posted at 5-27 03:44
Thanks,
here it is :
https://www.phantomhelp.com/LogViewer/8JLY5CUK3VFO42EBPS22/

You switched to sports mode and then, just before the large deviation, you moved your right stick to full back while also moving your left stick to full up.  So you're commanding your drone to climb as fast as possible while also fly backwards as fast as possible.  Such demands from the battery will increase the odds of a large cell deviation - and this is especially true in sports mode.  However it's not the deviation you have to worry about - it's the lowest cell.  If your lowest cell drops below 3.3 volts, your drone will start to Autoland.  If it drops below 3.0 volts, your drone will turn itself off.  Your lowest cell is nowhere near there - being at 3.916 volts.  Your battery appears to be perfectly healthy to me.   If the deviations make you uncomfortable, don't fly so aggressively.  This is especially a good idea towards the end of any flight when the total voltage of the battery is low since each cell will be closer to 3.3 volts.  Good luck.  

Mark The Droner Posted at 5-27 04:19
You switched to sports mode and then, just before the large deviation, you moved your right stick to full forward while also moving your left stick to full up.  So you're commanding your drone to climb as fast as possible while also fly backwards as fast as possible.  Such demands from the battery will increase the odds of a large cell deviation - and this is especially true in sports mode.  However it's not the deviation you have to worry about - it's the lowest cell.  If your lowest cell drops below 3.3 volts, your drone will start to Autoland.  If it drops below 3.0 volts, your drone will turn itself off.  Your lowest cell is nowhere near there - being at 3.916 volts.  Your battery appears to be perfectly healthy to me.   If the deviations make you uncomfortable, don't fly so aggressively.  This is especially a good idea towards the end of any flight when the total voltage of the battery is low since each cell will be closer to 3.3 volts.  Good luck.

Thanks for feedback

For what it's worth, the P3A I have was bought by my son in 2016 and we are still using the two original batteries he bought at the time.
I always use the supplied charger, no third party stuff to speed up charging. I always keep them topped up. If it's going to be idle for any length lof time I discharge to 50%