Seems difficult to find information about long term battery storage. The search engine doesn't seem to recognize my search description. My question is: What is the best percent of battery to store it for a few months? Or maybe you can direct me to where I can find this information. My battery manual is vague on this subject.
Thank you.

I would give it a full charge, then check at least monthly.  If it has fallen below 50%, then charge to full again.  This has worked good for me. Others will have different opinions.

ALABAMA Posted at 2018-2-3 16:10
I would give it a full charge, then check at least monthly.  If it has fallen below 50%, then charge to full again.  This has worked good for me. Others will have different opinions.

Thank you. What percentage do your batteries have after a month or so doing it that way?

Usually back to around 40% on average.

ALABAMA Posted at 2018-2-3 16:47
Usually back to around 40% on average.

Sounds like that will work. Thank you for your insight.

According to the P3S manual (pg 16) the battery will self discharge to below 65% in order to prevent swelling, which is also the same for the P4 batts, swelling is a major concern for LiPo batts.  
This discharge will occur in at most 10 to 12 days, for the P4s you can actually program the discharge to start sooner.  All of this means a couple of things, it makes no sense to put a battery in to long term storage fully charged as in a little more than a week it will simple reduce to below 65% and it could possibly lead to swelling in the process of waiting to discharge.  Most of the battery experts here have stated that you should store a batt at or around 50%, some say 30%.  Based on this information I choose to store mine at about 55% max.

an excerpt from this thread (note comment #33: https://forum.dji.com/thread-41951-1-1.html
-Is it OK to fully charge a battery and then store it for a few days or weeks, why or why not?  

This is the LiPo horror story ... fully charging and then not using. ANY length of time a LiPo is fully charged and stands - it starts to damage the cells. It does not magically wait so many days and then start. But it is generally accepted that a fully charged LiPo can be left for a day or so ... often the case with RC flyers who charge up night before / have unused packs and then fly 2 or 3 days later. BUT with DJI packs of course we have user settable auto discharge. I suggest that using DJI default of 10days is not good. I suggest a better setting is for battery to start auto-discharge 2 - 3 days after standing.
Another misunderstood point of the auto-discharge. It discharges to about 65% and then  keeps going ! It does not stop ... In fact it will keep going until it enters HIBERNATION MODE ...
Therefore it is suggested that battery be checked every few weeks if left for long periods.

Hope this helps

Thank you Genghis ... saved me typing it all out again !!

Cheers
Nigel

I think there is a natural discharge that occurs over time rather than the auto-discharge that brings it down initially.  It's very slow.  The evidence is in the P2 batteries which have no auto-discharge and yet will very very slowly lose their charge over time.  

Dirty Bird Posted at 2018-2-4 08:16
"Another misunderstood point of the auto-discharge. It discharges to about 65% and then  keeps going ! It does not stop ... In fact it will keep going until it enters HIBERNATION MODE ... "

I've never noticed this & in fact just checked my P3/P4 packs which haven't been charged in about 5 weeks.  They are all between 59-63% even after 5 weeks.

Hibernation mode is obtained after significant period. It basically is the lowest level allowed by the FW and effectively switches of the battery completely.

If you check the Battery manuals - you will see the sequence to awaken a Hibernation Mode battery.

Nigel

Dirty Bird Posted at 2018-2-4 08:16
"Another misunderstood point of the auto-discharge. It discharges to about 65% and then  keeps going ! It does not stop ... In fact it will keep going until it enters HIBERNATION MODE ... "

I've never noticed this & in fact just checked my P3/P4 packs which haven't been charged in about 5 weeks.  They are all between 59-63% even after 5 weeks.

I think it is great that your batts seem to hold their charge so well, but I know of no battery built by man that holds a charge forever and as Mark noted they will discharge slowly over time and I wont repeat Nigel's comments as he knows far more than I ever will on these batts.

The P4 Series Battery Charging Hub Charges or Discharges a battery to 50% when set to "Storage" mode. The manual states "Storage Mode allows the Charging Hub to keep the Phantom 4 Intelligent Flight Battery at a 50% charge, which is ideal for storage."

Jeff

Dirty Bird Posted at 2018-2-4 08:16
"Another misunderstood point of the auto-discharge. It discharges to about 65% and then  keeps going ! It does not stop ... In fact it will keep going until it enters HIBERNATION MODE ... "

I've never noticed this & in fact just checked my P3/P4 packs which haven't been charged in about 5 weeks.  They are all between 59-63% even after 5 weeks.

I was planning to go flying today, and last night I checked all three batteries and they were showing 4 LEDs. Today, I go to fly and one of the batteries is showing 1 blinking LED. So it looks like it auto-discharged over night. Too bad it take the included charger several hours to charge these. I wish there was a faster charge method.

Mark The Droner Posted at 2018-2-4 09:27
I think there is a natural discharge that occurs over time rather than the auto-discharge that brings it down initially.  It's very slow.  The evidence is in the P2 batteries which have no auto-discharge and yet will very very slowly lose their charge over time.

Exactly ... EVERY battery has what is called SELF DISCHARGE ... because a battery is basically a chemical process ... it is never idle even when disconnected.

A DJI battery will eventually discharge to near zero (2.8 - 2.9V per cell) and enter Hibernation mode. That is a mode designed to stop the cells reducing further .... but even that does not totally stop it.

This is why some battery bought will fail to charge because they have sat too long on shelf.

My preferred action is to fully charge ... then let auto discharge take over. Periodic checks after a month for example until the LED's get to 1 full + 1 flashing ... then charge up full again.

It is not necessary to be concerned about 50% charge ... anything from 30% to 55% is fine for storage and battery tech's in fact advise the lower range is better ...

Talk to any LiPo user in the RC world ... DJI batterys are only LiPo's with a fancy board slapped on the front to aid those who are new to the techno.

Nigel

BigBlueTsunami Posted at 2018-2-4 13:07
The P4 Series Battery Charging Hub Charges or Discharges a battery to 50% when set to "Storage" mode. The manual states "Storage Mode allows the Charging Hub to keep the Phantom 4 Intelligent Flight Battery at a 50% charge, which is ideal for storage."

Jeff

50% is ideal ... the reason for that statement is that 50% lies in the upper range of sensible storage and gives shortest time to recharge when needed.

The range of storage is from about 30 up to about 55% .... the best storage is in fact about 35% .... based on the LiPo fuel table.

Nigel

Mark Weiss Posted at 2018-7-22 08:55
I was planning to go flying today, and last night I checked all three batteries and they were showing 4 LEDs. Today, I go to fly and one of the batteries is showing 1 blinking LED. So it looks like it auto-discharged over night. Too bad it take the included charger several hours to charge these. I wish there was a faster charge method.

Yes you can charge faster by using a Programmable LiPo charger that has facility for LiPo High Voltage packs (commonly termed LiHV).

But it is advised not to go higher rate than 6 - 6.5A charge rate ... as the board fitted to the pack is not rated for much higher.

The 100W charger is the highest recc'd charge power to use and equates to :

100 / 15 = 6.7A in early stages while battery charges at low level ... reducing as voltage climbs .... at mid rate it is trying to push 6A in ...

The 57W standard charger of course doesn't get near this.
But to be honest - given the charge times observed - I believe the board is restricting more than calculated above ... so at end of day may not be possible to speed it up much. I tried with some of my chargers and they sat at around the 6A mark. I do not have higher powered to really push to confirm, but would be reluctant at price of a DJi battery !!

Nigel

solentlife Posted at 2018-7-22 09:17
Yes you can charge faster by using a Programmable LiPo charger that has facility for LiPo High Voltage packs (commonly termed LiHV).

But it is advised not to go higher rate than 6 - 6.5A charge rate ... as the board fitted to the pack is not rated for much higher.

I would be reluctant to have any high rate charging on these batteries, due to the increased danger of damaging a cell. It's a mission critical piece of the system.

It's unfortunate the DJI multiple charger only does one at a time though.

Apologies for resurrecting this older thread - but I just can't get my head around why the auto-discharge only lowers the charge to 65% and not to the best storage value of 35% identified by Nigel?

Surely achieving the optimal storage charge is the objective?!

Is it because there is the natural chemical discharging process and circuitry usage that occurs very slowly and the intention is to provide a 30% buffer before batteries begin to fall below the 35% value?

djiuser_FvVsSshTUBvo Posted at 8-22 07:47
Apologies for resurrecting this older thread - but I just can't get my head around why the auto-discharge only lowers the charge to 65% and not to the best storage value of 35% identified by Nigel?

Surely achieving the optimal storage charge is the objective?!

The DJI system auto discharges to about 60% ... but they know the discharge will still continue at a very low rate.
Having the battery go to 60% is a safe level for that setup.

Its a compromise of shorter recharge time when you want to use battery vs storage level.

I have stated 35% as optimum based on general LiPo use and battery manufacturers data. Remember DJI are not battery manufacturers. Its not something to worry about in fact as long as you set your auto discharge. My main reason for stating the 35% is to assure many who fly to 30 - 35% battery level when landed - that is fine for storage and no need to charge up more .... as long as you are not leaving batterys for month ! If you are leaving for extended period - then charge fully and let DJI setup look after it.

solentlife Posted at 8-22 12:10
The DJI system auto discharges to about 60% ... but they know the discharge will still continue at a very low rate.
Having the battery go to 60% is a safe level for that setup.

Thanks very much for sharing that answer - Now I understand  much better

Its always a compromise ... and DJI have decided to give you shortest charge time from storage while staying in the safe upper range of storage.