Lets talk battery life

[silverstoned83]

That's about the best climate to be in when you're cycling your new LiPo. I can see how cool enough outside air temps could reduce the effects of ignoring the break in period, but I still do not suggest it.

 

[elie kattar]

in my own experience, which i already posted before on this site, i had an issue with my first battery after 12 cycles, the thing is i didn't break in the lipo, i did discharge it to 15% once before its 10th cycle, stored it 2 days with 100% full charge, charged it directly after flight waited around 15min~20min only, well look at the surprise my battery started to degrade and eventually failed after its 15th cycle, i have followed the manual as provided by DJI didn't go on any exception, results are as follows:

Post 1
first signs of failure: http://www.phantompilots.com/threads/smart-battery-at-94-health-after-only-11-cycles.47473/
Picture:

Post 2:
second signs of failure: http://www.phantompilots.com/threads/87-health-14-cycles-only-really-sad.47730/#post-452110
Picture:

third sign of failure: battery Called out DOA by DJI here's the proof:
Picture:

DJI Answer:

New battery received performing Break-in in Process now, 4th cycle battery holding great flight time 12min 50% left, Storing at 50%, charging only before flights 1h~2h preflight, storing at average 22de
gree celsius, cooldown time 30min before charge, cell under load very close equally, waiting on my 12 cycle to compare it with the old one and prove that the break in process might have been the reason why i lost my old one and the low level drain i did also.

hope this helps
thanks

 

[silverstoned83]

Thanks for joining the debate! I can't help but see this as being a perfect example to support the break in theory. A LiPo that failed with over 10 cycles should not be considered defective, instead, operating conditions should be considered. How warm was the outside air temp during the first 10 cycles?

 

[elie kattar]

Thanks for joining the debate! I can't help but see this as being a perfect example to support the break in theory. A LiPo that failed with over 10 cycles should not be considered defective, instead, operating conditions should be considered. How warm was the outside air temp during the first 10 cycles?

I live in a place where its considered as Mediterranean breath meaning that temperature are superbly adequate for a phantom to fly with no issues, outside temperature 25 degree Celsius at peak when i fly, i never fly on mid days arround 12pm when the sun is at its peaks. Battery temperature never passed 44 to 48 degrees when under load

 

[N017RW]

Thanks for joining the debate! I can't help but see this as being a perfect example to support the break in theory. A LiPo that failed with over 10 cycles should not be considered defective, instead, operating conditions should be considered. How warm was the outside air temp during the first 10 cycles?

Don't look now, but your desperation is showing.

 

[silverstoned83]

I live in a place where its considered as Mediterranean breath meaning that temperature are superbly adequate for a phantom to fly with no issues, outside temperature 25 degree Celsius at peak when i fly, i never fly on mid days arround 12pm when the sun is at its peaks. Battery temperature never passed 44 to 48 degrees when under load

I'm surprised by the battery temps you were seeing. Are you sure that the temp didn't exceed 48°C when you drained it down to 15%? My two P3 LiPo's are at 48°C after a break in flight down to 50%. I would expect it to be much warmer if you drain it all the way down to nothing.

 

[elie kattar]

I'm surprised by the battery temps you were seeing. Are you sure that the temp didn't exceed 48°C when you drained it down to 15%? My two P3 LiPo's are at 48°C after a break in flight down to 50%. I would expect it to be much warmer if you drain it all the way down to nothing.

Fyi the last time i drained it to 10% when dji asked me to do so, my phantom shut off mid air and went down like a rock luckily i was hovering it 10feet of ground, and yes you are right that time precisely when i did perform this drain, the battery temperature rised fast but i didnt screen shot it, as it happened in a matter of seconds just before my phantom fell from system power cut off, I wish i had taken the shot before but as i am saying while under normal load flights 48 degree was the maximum recorded.

 

[GordonT]

Lithium polymer batteries don't actually benefit from being broken in. They don't recognise this process in the way an internal combustion engine does as it overcomes initial wear through manufacturing tolerances for example. The chemistry is set at the start to the working process and size.
They suffer from excessive temperature, over discharge, and being left fully charged.
Breaking in isn't a factor.

 

[Dome]

Yesterday I had a skype discussion with an ex-collegue (a great friend of mine)... He is a LiPo guru and he's working free-lance at LiPol Battery Co in Shenzen this year ..
I was too curious to know why we never took into account the "break-in" effect during test, experiments, life duration, buying cells, driving electronics and so on.
Making the story short, he explained me that "break-in" DOES exist and it is a good practice on post-formation cells (RC multi-cells battery for example), that were shipped with a conservative chemical (vinyl-carbonate) inside the folded cell sheets. This chemical prevent storage degradation of newly charged cells before shipping. In this case break-in is good to start-up a battery, avoiding high current charge and too high temperature, so that chemical is completely eliminated, attaching it to graphite anode. As a result the Z (impedance NOT resistance, measured with elctrochemical impedance spectroscopy) will get lower, because anode is going to be better conductive. As an example, 4-5 times of half or 3/4 normal charge is more than enough.
On the other hand new production process, trimmed on the last 4-5 years, doesn't use anymore post-formation chemicals to preserve charge. I think (and I hope) P3 battery falls in this second case.

At the end, I think @silverstoned83 is quite right, in his experience !!

In our experience cells can fail unitl 10 cycle, unfortunately, and they were replaced at a rate of 1% base.

This is a technical datasheet example we receive with battery cells:
https://www.batteryspace.com/prod-specs/ICR18650NH-2200.pdf

In this image I have (this is new production process study) in my docs, shows what's happening during formation. As you can see as soon as reached 0.15V threshold, impedance of the first cycle and 10th cycle are absolute overlaying. I hope to have clarified a bit.

 

[GordonT]

So the p3 Lithium polymer battery doesn't need a break in procedure due to the modern day process of manufacture. Funny that, it's the same as the automotive engine. They make them to size and shape now so accurately that the tolerances are set close to operational limits, unlike the old days. Same with Lipo batts.

 

[sinxa]

I got 48cycles and 88% life.
I thought i've treat it carefully.
Full charge before flight. Keep about 50% while not in use for a while. Fly with it through about 25% left when landed. Do deep discharge to below 10% once for every 20 cycles.

But i think i've seen the battery performance degrades. It only hold 40xx mAh on full charged. And shows "maximum propulsion warning" few times even i have not pushed it to full throtle. And i can see the quad ascend or move slightly slower than it used to (less than 3m/s ascend).

Is it the time to replace it? Anybody experience the same?

Sent from my SCL23 using PhantomPilots mobile app

 

[Mark The Droner]

Well done on the bump.

With 40xx mAh, I would not necessarily retire it, but I'd use it gently and only for relatively short flights. I'd definitely get a new battery for harder uses. MHO