A friend sold me a high capacity battery with few charges.. I'd like to be sure it has no problem on its cells..
Battery 42%, 3,7V all cells and green..with the drone idling at 1 mt height Voltage is 3,5V on all cells and all are yellow, sometime they change to 3,4V and all red... is it normal!?
I don't know if I need a reset or is a damaged battery so to sent it back to my friend...I also discovered the warning about voltage in the picture below

Hard to understand your post.  Sounds like you launched your drone with about a 42% charge?  You can't do that.  

Try fully charging your battery, then launch, then look at the data.  

Good luck

yes! I tried the battery with 42% (just 1 meter) to check the cells status..then now it's reached 8% and I'm charging the battery.. tomorrow I'm gonna try it from 100% as it has to be done, I know it

What Phantom model do you have ?

Manu P4P Paris Posted at 12-9 10:53
yes! I tried the battery with 42% (just 1 meter) to check the cells status..then now it's reached 8% and I'm charging the battery.. tomorrow I'm gonna try it from 100% as it has to be done, I know it

Please - I suggest you do not take your battery down to 8% .....

Full charge before any flight
Fly to not less than 15% .... I prefer 30% but that's me.
Storage level from 30% to 50% ... best way there is to set auto discharge days to 2 or 3 .. charge up full and then leave to auto discharge. Leave it alone till next needed.

it's a P4P..consider that my low battery warning is always set to 30% so as soon as I have the alarm I land and my max distance is always less than 300mt..so we are on the same page! discharge time 2 days!
everywhere I read to reach 8% for a reset..but as veteran with lipo batteries, it's a contradiction since it's not safe to discharge the battery to very low voltages...

Manu P4P Paris Posted at 12-9 13:02
it's a P4P..consider that my low battery warning is always set to 30% so as soon as I have the alarm I land and my max distance is always less than 300mt..so we are on the same page! discharge time 2 days!
everywhere I read to reach 8% for a reset..but as veteran with lipo batteries, it's a contradiction since it's not safe to discharge the battery to very low voltages...

There's nothing about 8% in the P4P battery doc

https://dl.djicdn.com/downloads/ ... y+Guidelines+En.pdf

However, it's mentioned on page 34 of the P4P manual.

https://dl.djicdn.com/downloads/ ... _User_Manual_EN.pdf

My opinion is the same as Solentlife.  Don't do it.   

Ok thanks..never did in years and I didn’t in time yesterday! I just thought was a correct method..
Anyway, I hope to don’t see any strange cells behavior today with a full charge battery!

Aaahhh,  nothing like the "Old Battery Scenario"  to find contradictions.
Haven't seen many battery posts of late.

The only justification for a deep discharge is to reset the chip counter ... as said - LiPo users are well versed in NOT deep discharging if they want long life batterys.

There is one saving grace though ... The DJI battery will shut down if it hits 3.0v cells ... still not a good thing to do - but at least it goes some way to save it.

solentlife Posted at 12-10 08:46
The only justification for a deep discharge is to reset the chip counter ... as said - LiPo users are well versed in NOT deep discharging if they want long life batterys.

There is one saving grace though ... The DJI battery will shut down if it hits 3.0v cells ... still not a good thing to do - but at least it goes some way to save it.

Provided it's not 400 feet up when it happens  

Mark The Droner Posted at 12-10 10:08
Provided it's not 400 feet up when it happens

Too true !!

Manu P4P Paris Posted at 12-9 10:53
yes! I tried the battery with 42% (just 1 meter) to check the cells status..then now it's reached 8% and I'm charging the battery.. tomorrow I'm gonna try it from 100% as it has to be done, I know it

A deep cycle won’t hurt the flight pack, but will reset the internal clock.


This has been discussed and argued about for several years already.

https://forum.dji.com/thread-89494-1-1.html

RedHotPoker

RedHotPoker Posted at 12-10 22:02
A deep cycle won’t hurt the flight pack, but will reset the internal clock.

You do that Deep Cycle too many times or too often ... and you can get your money out for replacement.

The fact that 3.0v x 4 (12V) is the cut off programmed into the packs control board is no g'tee of one or more cells going lower. Myself and another club member tested this and we found one cell dropped to just over 2.8V while the other 3 were over 3.0v .... giving the magic 12V cut off total.  We were shocked, as we expected the board to work via individual cells as a Programmable Charger does.

Manu P4P Paris Posted at 12-9 10:53
yes! I tried the battery with 42% (just 1 meter) to check the cells status..then now it's reached 8% and I'm charging the battery.. tomorrow I'm gonna try it from 100% as it has to be done, I know it

For the record, the manual does not say to discharge the battery until "it's reached 8%."  The manual says to discharge "...until there is less than 8% of power left...", which means at least 7%, and I've seen 3% argued as a good target.  And from what I've read, it matters.  There is something triggered when one brings the battery below 8% which isn't triggered when one brings the battery only to 8%.  I read this years ago in a P2 thread from a guy who did extensive testing on this.  

Nonetheless, my experience and the experience of a lot of other guys is that discharging a battery to very low levels eats maximum mAh, which is to say, the battery won't stay on as long in later flights.  This can be confirmed by studying the battery data in your logs before and after.  Deep discharging repeatedly will give the battery an early death.  That's my experience.  

But due to differing opinions and also the strange and obvious contradictions in the manual, you'd be happier if you did your own research.  

Good luck

I have boxes of lipos ... of all sorts of sizes and capacity for all sorts of RC and other duties. The one rule that LiPo users have in RC is that they take care not to discharge too low and to not overload them. The addition of a board on the front end of a DJI battery does not change the fact its a LiPo behind it.

They then enjoy happy life with them.

solentlife Posted at 12-11 04:18
You do that Deep Cycle too many times or too often ... and you can get your money out for replacement.

The fact that 3.0v x 4 (12V) is the cut off programmed into the packs control board is no g'tee of one or more cells going lower. Myself and another club member tested this and we found one cell dropped to just over 2.8V while the other 3 were over 3.0v .... giving the magic 12V cut off total.  We were shocked, as we expected the board to work via individual cells as a Programmable Charger does.

Upvote...

To be honest,
I have never deep cycled any of my 4, DJI flight packs. Wicked grin

Fa fa fa, fooling... hahaha


So any concurrent damage incurred, was never an issue for me.

End of subject. Period



RedHotPoker

Manxmann Posted at 12-10 01:40
Aaahhh,  nothing like the "Old Battery Scenario"  to find contradictions.
Haven't seen many battery posts of late.

I don't follow your humour..it's not an old battery, only 7 cycles in few months.. I just want to be sure it's ok

Mark The Droner Posted at 12-11 04:27
For the record, the manual does not say to discharge the battery until "it's reached 8%."  The manual says to discharge "...until there is less than 8% of power left...", which means at least 7%, and I've seen 3% argued as a good target.  And from what I've read, it matters.  There is something triggered when one brings the battery below 8% which isn't triggered when one brings the battery only to 8%.  I read this years ago in a P2 thread from a guy who did extensive testing on this.  

Nonetheless, my experience and the experience of a lot of other guys is that discharging a battery to very low levels eats maximum mAh, which is to say, the battery won't stay on as long in later flights.  This can be confirmed by studying the battery data in your logs before and after.  Deep discharging repeatedly will give the battery an early death.  That's my experience.  

Thanks! yeah I cleared my doubts with few words here..

Manu P4P Paris Posted at 12-12 12:39
I don't follow your humour..it's not an old battery, only 7 cycles in few months.. I just want to be sure it's ok

Sorry Manu,  I meant the Battery Scenario was old as in repeated ad nauseam. I didn't intend any inference as to the age of your batteries.
It's just that in the past there have been soooooo many posts about batteries and their various conditions I find it entertaining.  It's just my weird sense of humour !    

Sorry no ill intended  

Ok..I know there are so many users with this battery concern..in fact, it’s the first time I talk about it after 5 years..!! Maybe because it’s my first used battery!!