Mini 4 pro plus battery storage

[jmc667]

Good morning everybody. Looked around but couldn't find any info here. I just got my Mini 4 pro w/ plus batteries. I have everything updated and batteries charged. It's been 10 days, and the batteries self discharged to 3 solid green lights. Is the 10 days correct? and is 3 solid green lights where it should be? Or should it be 2 solid, and 1 flashing. Just checking. I haven't flown yet as the weather here has been pretty crappy. I read the manual, and under the battery section it could be 3 solid or 2 solid 1 flashing for 60 ish % for storage.

 

[Cafguy]

I would purchase something like this:

This is the Hanatora charger for the Mini 4. It comes with a storage charge/disharge switch to keep your batteries stored at 60 percent.
You can damage your battery letting it self-discharge- these batteries do NOT discharge at a rate that prevents eventual damage. There are tons of sad dead battery stories that could have been prevented by having a charger with a storage option.

 

[jmc667]

Thanks cafguy, I have that co.s charger/ discharger for my Air2s batteries, as I'm also not convinced about the 10 days to discharge. I also feel that this is too long. Thanks for the info

 

[LongRifle]

That Hanatora charger is really nice to have your battery maintenance done automatically. I just manually maintain my batteries by charging them up once a month and discharging them using the USB adapter to charge my phone, tablet or any device that uses USB. I have 7+ years old original Mavic Pro batteries that are still in good shape by simply doing that.

 

[DrMichelson]

Intersting. I'm still flying a Mavic Air 1...bought it in 2019. I bought 4 batteries and the drone and batteries work like new. I've always just left them on my 4 battery charger (that came with the Air) and actually did not use them - keeping them on the charger for 2 years. [Now having fun with it again] This is a great drone and I get to check my bee hives 3/4 quarter miles away in the winter (30 degrees). ...love this drone...

 

[MotoSavy]

They are intelligent batteries and discharge on their own. No need to be concerned. According to the manual two solids and one flashing indicate 51%-62% charged during charging and discharging

From the MINI 4 users Manual: (only relevant sections posted)

Auto-Discharging Function: to prevent swelling, the battery automatically discharges to 96% battery level when it is idle for three days and automatically discharges to 60% battery level when it is idle for nine days. Note that it is normal for the battery to emit heat during the discharging process.

Over-Discharge Protection: discharging stops automatically to prevent excess discharge when the battery is not in use. Over-discharge protection is not enabled when the battery is in use.

Hibernation Mode: if the battery is less than 10% when the aircraft is idle, the battery enters Hibernation mode to prevent over-discharge. Charge the battery to wake it from hibernation.

You can download the Users manual at: DJI Mini 4 Pro - Download Center - DJI

 

[jmc667]

They are intelligent batteries and discharge on their own. No need to be concerned. According to the manual two solids and one flashing indicate 51%-62% charged during charging and discharging

From the MINI 4 users Manual: (only relevant sections posted)

Auto-Discharging Function: to prevent swelling, the battery automatically discharges to 96% battery level when it is idle for three days and automatically discharges to 60% battery level when it is idle for nine days. Note that it is normal for the battery to emit heat during the discharging process.

Over-Discharge Protection: discharging stops automatically to prevent excess discharge when the battery is not in use. Over-discharge protection is not enabled when the battery is in use.

Hibernation Mode: if the battery is less than 10% when the aircraft is idle, the battery enters Hibernation mode to prevent over-discharge. Charge the battery to wake it from hibernation.

You can download the Users manual at: DJI Mini 4 Pro - Download Center - DJI

Thanks so much. I've read every page of the manual several times.

 

[BigAl07]

Thanks cafguy, I have that co.s charger/ discharger for my Air2s batteries, as I'm also not convinced about the 10 days to discharge. I also feel that this is too long. Thanks for the info

10 days isn't bad at all. This is a good compromise between good mattery maintenance and being overly aggressive. The fact it drops them to 96% after 3 days is a key factor for longevity.

But, with that being said, if you want to take FULL CONTROL of your battery maintenance there's nothing stopping your from MANUALLY discharging them to a safe storage mode on day 1, 2 ,3, or whatever you want prior to day 9/10.

 

[Droning on and on...]

You can damage your battery letting it self-discharge- these batteries do NOT discharge at a rate that prevents eventual damage.

Could you give some detail about why you believe this? I strongly disagree, and have quite a bit of experience with the characteristics of lipos, cylindrical li-ion cells, BMS's, etc., as I've been designing and manufacturing power banks for years, especially for custom applications.

In my opinion, the BMS in DJI Intelligent Batteries is among the best, and only matched, high quality cells are used.

The discharge/storage protocol programmed into the BMS is as optimal as you can get. Discharging to 60% slowly over several days is much less stressing to the battery than deliberately discharging over a few hours to 60%.

In my opinion, If you only use a battery a few times a week, the BEST strategy to getting as much cycle life and retained capacity is to fully charge after a flight and leave it alone. The BMS will take it down to 95% in a day or two, then slowly discharge to storage (60%) after 10 days.

The biggest stress, and "wear" on a lipo is high current, which occurs during charging, and use. Minimize current flow through the battery. Charge slowly overnight with a 15W PD charger. Always let the self-discharge slowly discharge to storage level.

The other benefit of this is that if plans change and you want to fly before storage discharge has completed, you will charge less, thereby pushing less current overall through the battery, preserving it's life.

The best principle for DJI Intelligent Batteries is to have them on the charger for as few total hours over its life as possible. Don't waste mWh heating the Hantora charger using discharge mode.

The worst thing you can do is store them uncharged. Or, the equivalent, store them away for years and they naturally discharge completely and die.

Otherwise, just always fully charge after use and put them away.

There are tons of sad dead battery stories that could have been prevented by having a charger with a storage option.

No, I don't believe this is true. Yes for people forgetting to charge a depleted battery and storing it for months, no for fully charged batteries stored and allowed to discharge to storage under the control of the BMS.

 

[mobilehomer]

The doomsayers of battery discharge base their beliefs on the batteries used for RC planes, helicopters, cars and such. The 2 cell, 4 cell and others that require a balanced charge and discharge because they do not have an onboard BMS.

 

[Cafguy]

In the Drone security business Batteries are your biggest expense. I use an Air 2s and have gone thru too many batteries too count. I have gotten my 200 cycles for almost every one of them- except for a few flukes and the first set I owned which I used to charge to 100% after use and put in the case. The rest were, Charged-used-charged to storage of 60% until the next use and monitored and then used again- No lost Cycles. Many experts will tell you that you can ultimately lose some of your cycles by charging them and leaving them to thier own devices. I have read many articles on the subject and I think this to be Correct.
I will only say to Test it for yourself: Take a battery and treat it as you would normally and Then take a second one and do as I recommend, at the end of each Batteries life see how many charge cycles you got out of each.
If you have been designing and building these lipos for years (and I do not question that) then perhaps you can tell me why many have had the same experience I have had with these Batteries and have elected to buy a charger with a Storage Option. I would be fine giving up my routine and doing something Better for sure.

 

[Droning on and on...]

10 days isn't bad at all. This is a good compromise between good mattery maintenance and being overly aggressive. The fact it drops them to 96% after 3 days is a key factor for longevity.

^^This.

In terms of dendritic growth – which is what kills lipos in the context we're discussing – at 95% charge there's no meaningful difference between 2 days and 10. In this time range it's much, much, MUCH more important how much power goes through the cell, in either direction. This translates directly to current.

Quick definition related to batteries that many may not be familiar with: "C" rating. This is the rated capacity number (milliamp-hours) interpreted as a current (milliamps). Charge and discharge "speed" in terms of current is expressed as some multiple of C.

A typical RC lipo may have a discharge rating of 30C, while limited to anywhere between 0.1C-1C charge rate.

This means a 4000mAh battery as above can discharge as high as 120A, charge between 400-4000mA. Battery that charges full from depleted in 1 hour is charging at 1C.

The best way to shorten the life of your battery is to use it. The only way really to reduce the high-current stress on a battery is to charge very slowly – C/10 is about as slow as needed, not much gain at all at lower currents – and if discharging for storage, same.

This is what the internal BMS does. 3rd party chargers with a discharge feature do it much faster, which is much more stressful and "damaging" to the battery than sitting at 95% for 10 days.

But, with that being said, if you want to take FULL CONTROL of your battery maintenance there's nothing stopping your from MANUALLY discharging them to a safe storage mode on day 1, 2 ,3, or whatever you want prior to day 9/10.

And really accomplishing nothing in terms of battery preservation... In my opinion, actively discharging to 60% will marginally reduce battery life.

 

[Droning on and on...]

If you have been designing and building these lipos for years (and I do not question that) then perhaps you can tell me why many have had the same experience I have had with these Batteries and have elected to buy a charger with a Storage Option. I would be fine giving up my routine and doing something Better for sure.

Given your use, I'd stick with your protocol. However, the big difference is the frequency of use.

The physics and chemistry, however, simple are what they are. What wears a lipo is high current. That's when dendrites form... when there are ginormous numbers of lithium ions flooding between anode and cathode.

Professional, near-daily use will wear them the fastest.

 

[Cafguy]

Thanks for that and I would also mention I have little experience with the series 3 and above Batteries except for using someone elses drone.

 

[BigAl07]

Professional, near-daily use will wear them the fastest.

That's a FACT! Even "gentle" daily use is still daily use. Our organization goes through batteries way more often simply because we use (aka charge/discharge) them every single day. While we do try to be "gentle" but it's "Use" none-the-less. We still get high into the # of charge/discharge cycles but we get to those #'s quicker than most.

For others reading this, keep in mind that regardless of how you maintain your battery, it has a FINITE # of charges and discharges before you start seeing an appreciable amount of degradation. The more "kind" you are to your batteries, the better your odds are for getting into the higher range of charge/discharge cycles and the more abusive your are (intentional or not) the low that potential # of charge/discharges become. This is why some people can do many months or more with a battery type and some, in rate instances, can PUFF a battery in just a few flights. It's HOW you treat your batteries that has the most profound effect on battery longevity.

 

[Cafguy]

Our organization goes through batteries way more often simply because we use (aka charge/discharge) them every single day.

That was me when I first started! Everyday, sometimes twice a day for some of them and I would keep 8 ready to go and 8 at 60 ready to go into the charger if needed. The good part about security is that once you have covered a place pretty often and vary your times, you won't have to fly around as much later- therefore saving you some good money..

 

[jmc667]

Could you give some detail about why you believe this? I strongly disagree, and have quite a bit of experience with the characteristics of lipos, cylindrical li-ion cells, BMS's, etc., as I've been designing and manufacturing power banks for years, especially for custom applications.

In my opinion, the BMS in DJI Intelligent Batteries is among the best, and only matched, high quality cells are used.

The discharge/storage protocol programmed into the BMS is as optimal as you can get. Discharging to 60% slowly over several days is much less stressing to the battery than deliberately discharging over a few hours to 60%.

In my opinion, If you only use a battery a few times a week, the BEST strategy to getting as much cycle life and retained capacity is to fully charge after a flight and leave it alone. The BMS will take it down to 95% in a day or two, then slowly discharge to storage (60%) after 10 days.

The biggest stress, and "wear" on a lipo is high current, which occurs during charging, and use. Minimize current flow through the battery. Charge slowly overnight with a 15W PD charger. Always let the self-discharge slowly discharge to storage level.

The other benefit of this is that if plans change and you want to fly before storage discharge has completed, you will charge less, thereby pushing less current overall through the battery, preserving it's life.

The best principle for DJI Intelligent Batteries is to have them on the charger for as few total hours over its life as possible. Don't waste mWh heating the Hantora charger using discharge mode.

The worst thing you can do is store them uncharged. Or, the equivalent, store them away for years and they naturally discharge completely and die.

Otherwise, just always fully charge after use and put them away.



No, I don't believe this is true. Yes for people forgetting to charge a depleted battery and storing it for months, no for fully charged batteries stored and allowed to discharge to storage under the control of the BMS.

so not to stir the pot but, I read somewhere this guy flies a fully charged battery, then charges only to 60% for storage after flight. Then fully charges before next flight. What's wrong with this picture? I'm guessing not a complete cycle of the battery. It just seems to be a waist of a cycle by fully charging then letting it sit 10 days to discharge. I'm learning a lot about these batteries from you guys. I guess I need to trust DJI. They have served me well for almost 15 years.

 

[MotoSavy]

so not to stir the pot but, I read somewhere this guy flies a fully charged battery, then charges only to 60% for storage after flight. Then fully charges before next flight. What's wrong with this picture? I'm guessing not a complete cycle of the battery. It just seems to be a waist of a cycle by fully charging then letting it sit 10 days to discharge. I'm learning a lot about these batteries from you guys. I guess I need to trust DJI. They have served me well for almost 15 years.

I think that is fine if you don't plan to fly for a while or are willing to wait the longer time to charge them if you decide to fly in a few days. I see no harm in it and would actually reduce the total number of battery cycles.

 

[Droning on and on...]

so not to stir the pot but, I read somewhere this guy flies a fully charged battery, then charges only to 60% for storage after flight. Then fully charges before next flight. What's wrong with this picture? I'm guessing not a complete cycle of the battery. It just seems to be a waist of a cycle by fully charging then letting it sit 10 days to discharge. I'm learning a lot about these batteries from you guys. I guess I need to trust DJI. They have served me well for almost 15 years.

If you know you won't be using the battery for 15 days, it would be better to only charge it to 60%.

Thing is, most of us don't know that.

 

[jmc667]

OK thanks guys. I think I'll try that as long as like you say, I don't plan to use the battery for awhile.