I've mentioned this under another topic but I didn't get any answers there so I'm promoting it to hopefully solve the mystery.
My 2-month old M4P/RC2 came with one standard battery which I have never removed from the drone. Maybe I'm not alone in this – I don't fly often and always very locally.

I quickly discovered that my new battery gave me 5-10 minutes more flight time than my old M3P battery, which was an unexpected bonus. But then came the mystery. I was ill with flu for several weeks and couldn't fly, so my fully charged M4P sat idly on my desk. I would occasionally push the test button to check how quickly the charge was draining…but all four lights stayed resolutely illuminated. Eventually, with bad weather conspiring to keep my drone idle for four weeks, I took it out for a flight in my back yard - still inexplicably reporting a full charge - expecting to find that the battery was faulty. But no, the RC reported a 92% charge with all systems go so off we went.

Has anyone else experienced this? My old M3P battery would lose one or two lights per week if left idle in the same way. Am I perhaps seeing a benefit of the M4P's new Eco mode? Or is the new, lighter M4P battery a different type of Li-on battery? (The Lithium battery in my e-moped behaves in the same way: I can leave it in situ and lose no charge even if I don't drive the moped for three months.)

I think I read somewhere that after 9days after being fully charged up and not used, the "smart" part of the battery will discharge down to it's 60% storage capacity. I noticed with mine, if I top them off and fly a few days later, the batteries will be about 92-96%full.

You pressing the button (to check it) resets the timer

I do wish people would not post threads like this, 9 times out of 10 they jinx themselves.

I wish people would read the MANUAL !

I would occasionally push the test button to check how quickly the charge was draining
And that's the issue.
Each time you check, you set the timer back to zero .

You've made sure that the battery wouldn't discharge and in doing so have harmed it a little.
Lithium batteries shouldn;t be left fully charged or run down.
Stop checking and let the battery circuitry do its thing and discharge if you aren't going to fly.

Labroides Posted at 12-6 12:57
I would occasionally push the test button to check how quickly the charge was draining
And that's the issue.
Each time you check, you set the timer back to zero .

That would depend how often I checked and since I twice left it unchecked for more than 9 days, the battery should have discharged to at least 60% - which it didn't.

Btw, maintenance instructions are to regularly check the battery level indicators.

By the way it is unwise to fly to distance etc. on an old charge as it may drop suddenly and you could end up with the drone in a forced landing somewhere. To me 4 weeks would be an old charge.
If you have charged the battery and can not fly it out of doors for a few days I would do an indoor hover, in a well lit and clutter free room, for a few minutes to burn of some charge.

Labroides Posted at 12-6 12:57
Each time you check, you set the timer back to zero .

Will the battery auto discharge in the drone?

Sean-bumble-bee Posted at 12-6 15:29
Well the battery auto discharge in the drone?

My old M3P battery certainly did but this M4P battery seems to be a very different animal. FWIW, I don't think there's anything in the M4P manual which says you shouldn't store a battery in the drone - which would be consistent with my other Li-on powered equipment including my e-moped and various Black & Decker and De Walt tools, all of which continue to function optimally when stored for extended periods with full or partially charged batteries inserted. I assume the same is true of Tesla and other e-cars.

Bashy Posted at 12-6 07:30
You pressing the button (to check it) resets the timer

What would be the logic for that? I would have expected the auto-discharge timer to ignore button presses - especially if the discharge cycle is critical to battery health.

trainee Posted at 12-6 23:19
My old M3P battery certainly did but this M4P battery seems to be a very different animal. FWIW, I don't think there's anything in the M4P manual which says you shouldn't store a battery in the drone - which would be consistent with my other Li-on powered equipment including my e-moped and various Black & Decker and De Walt tools, all of which continue to function optimally when stored for extended periods with full or partially charged batteries inserted. I assume the same is true of Tesla and other e-cars.

Corrected the spelling mistake whoops.
With regards to flying on an old charge and your B&D and De Walt power tools, all I will say is you have been warned what might happen.
It's up to you if and where you fly on an old charge but your tools can't enter a forced landing mode over somewhere where you can't recover them, your drone might.

Sean-bumble-bee Posted at 12-6 15:28
By the way it is unwise to fly to distance etc. on an old charge as it may drop suddenly and you could end up with the drone in a forced landing somewhere. To me 4 weeks would be an old charge.
If you have charged the battery and can not fly it out of doors for a few days I would do an indoor hover, in a well lit and clutter free room, for a few minutes to burn of some charge.

'trainee' doesn't mention that they have the charging hub so maybe not relevent for them, but a note for those that do...

The charging hub is two way so can be used as a power bank to charge a phone or tablet etc. That's a useful way to discharge any charged drone batteries that aren't going to be used for a while

No Original Thought Posted at 12-7 01:15
'trainee' doesn't mention that they have the charging hub so maybe not relevent for them, but a note for those that do...

The charging hub is two way so can be used as a power bank to charge a phone or tablet etc. That's a useful way to discharge any charged drone batteries that aren't going to be used for a while

I did wonder about their having a hub but thought it was unlikely since they wrote "which I have never removed from the drone."
I use the mini 1 & 2 hubs to do the same thing.

Sean-bumble-bee Posted at 12-7 01:02
Corrected the spelling mistake whoops.
With regards to flying on an old charge and your B&D and De Walt power tools, all I will say is you have been warned what might happen.
It's up to you if and where you fly on an old charge but your tools can't enter a forced landing mode over somewhere where you can't recover them, your drone might.

I'll take your word for it and bear this in mind but it wouldn't be a major issue for me as I invariably fly within 500m of my home over open fields. Meanwhile, as an infrequent flyer, I'm finding it very convenient that the battery holds onto its charge in a parked drone and it is saving me a lot of charging cycles. If and when it transpires that my battery abuse shortens its life, I'll buy another and consider it money well spent.

Hello, there. Thank you for sharing your query with us. The DJI Mini 4 Pro supports Auto-Discharging Function: the battery automatically discharges to approximately 96% of the battery level when it is idle for three days, and approximately 60% when idle for nine days. It is normal to feel moderate heat from the battery while it is discharging. Please know that the auto-discharging will be interrupted after pressing the power button. To test the battery further, you may consider idling the Intelligent flight battery within the said days to check the performance. Please feel free to let us know about the latest progress. Thank you for your support!

trainee Posted at 12-7 01:38
I'll take your word for it and bear this in mind but it wouldn't be a major issue for me as I invariably fly within 500m of my home over open fields. Meanwhile, as an infrequent flyer, I'm finding it very convenient that the battery holds onto its charge in a parked drone and it is saving me a lot of charging cycles. If and when it transpires that my battery abuse shortens its life, I'll buy another and consider it money well spent.

fair enough

DJI Gamora Posted at 12-7 02:37
Hello, there. Thank you for sharing your query with us. The DJI Mini 4 Pro supports Auto-Discharging Function: the battery automatically discharges to approximately 96% of the battery level when it is idle for three days, and approximately 60% when idle for nine days. It is normal to feel moderate heat from the battery while it is discharging. Please know that the auto-discharging will be interrupted after pressing the power button. To test the battery further, you may consider idling the Intelligent flight battery within the said days to check the performance. Please feel free to let us know about the latest progress. Thank you for your support!

Thanks. Just for clarification, what harm, if any, could be done to a fully charged battery by leaving it an idle drone for up to three months, say?

And why does the auto-discharge timer reset after a tap on the power button to check the charge level? This would appear to do potentially more harm than good.

trainee Posted at 12-6 23:29
What would be the logic for that? I would have expected the auto-discharge timer to ignore button presses - especially if the discharge cycle is critical to battery health.

I do hope that you will take my word for it too, pressing the button will 100% reset the timer.

trainee Posted at 12-7 03:03
Thanks. Just for clarification, what harm, if any, could be done to a fully charged battery by leaving it an idle drone for up to three months, say?

And why does the auto-discharge timer reset after a tap on the power button to check the charge level? This would appear to do potentially more harm than good.

No harm will come to the battery, it will gradually lose charge over time, leave it too long and it fully discharges then you may not be able to recharge it, therefore, it is dead for good.

No harm will come to the battery when you press the button, I have done it since i got my 1st P4P, i have 4 batteries with it that i check periodically, i have not flown it in well over a year and the batteries are still good, I check every month and i will recharge them at least once a year. My Mini 3 Pro is the same, i have 3 standard and one Plus battery, I've not flown it for at least 8 months and all 4 are in good working order, i do the exact same with that as i do the P4P.

Touching wood, i have never had a battery go bad except for one that i dropped 3 times in one day, it broke the terminals and shorted out and wouldnt charge again.

Gamora will confirm that its ok to press the button

Bashy Posted at 12-7 04:29
No harm will come to the battery, it will gradually lose charge over time, leave it too long and it fully discharges then you may not be able to recharge it, therefore, it is dead for good.

No harm will come to the battery when you press the button, I have done it since i got my 1st P4P, i have 4 batteries with it that i check periodically, i have not flown it in well over a year and the batteries are still good, I check every month and i will recharge them at least once a year. My Mini 3 Pro is the same, i have 3 standard and one Plus battery, I've not flown it for at least 8 months and all 4 are in good working order, i do the exact same with that as i do the P4P.

I wasn't actually questioning whether it was OK to press the button. I assumed it must be since the manual tells us to do so regularly. I was asking Gamora about any possible harm that could arise from leaving a fully charged battery in the drone for an extended period of inactivity - and also the logic of resetting the auto discharge cycle when pressing the button.

The mystery here is that my battery remained fully charged even without pressing the power button for 12 days on one occasion and 10 days on another (with up-to-date firmware).

trainee Posted at 12-7 04:40
I wasn't actually questioning whether it was OK to press the button. I assumed it must be since the manual tells us to do so regularly. I was asking Gamora about any possible harm that could arise from leaving a fully charged battery in the drone for an extended period of inactivity - and also the logic of resetting the auto discharge cycle when pressing the button.

The mystery here is that my battery remained fully charged even without pressing the power button for 12 days on one occasion and 10 days on another (with up-to-date firmware).

Then check to see if you can do the FW update again as it may not have taken...

Sean-bumble-bee Posted at 12-6 15:29
Will the battery auto discharge in the drone?

Sorry, i missed this, Yeah, it will in the drone or the hub.

trainee Posted at 12-7 04:40
I wasn't actually questioning whether it was OK to press the button. I assumed it must be since the manual tells us to do so regularly. I was asking Gamora about any possible harm that could arise from leaving a fully charged battery in the drone for an extended period of inactivity - and also the logic of resetting the auto discharge cycle when pressing the button.

The mystery here is that my battery remained fully charged even without pressing the power button for 12 days on one occasion and 10 days on another (with up-to-date firmware).

I assumed it must be since the manual tells us to do so regularly.
You are referring to the very vague mention on p 111 of your manual which says:
Regularly check the Battery Level Indicators to see the current battery level and overall battery life.
Your idea of regularly and DJI's are likely very different.
It's not something you need to do twice a week or even once a month.


I was asking Gamora about any possible harm that could arise from leaving a fully charged battery in the drone for an extended period of inactivity - and also the logic of resetting the auto discharge cycle when pressing the button.
You won't get any technical information from the moderators.
In the uncommon event that they offer some, it's likely to be incorrect.

Bashy Posted at 12-7 17:28
Sorry, i missed this, Yeah, it will in the drone or the hub.

Cheers Bashy.

Labroides Posted at 12-7 17:46
I assumed it must be since the manual tells us to do so regularly.
You are referring to the very vague mention on p 111 of your manual which says:
Regularly check the Battery Level Indicators to see the current battery level and overall battery life.

Not more frequently than once every 10 days anyway… But that's a deduced number and the manual needs to be more specific on this topic.

trainee Posted at 12-7 03:03
Thanks. Just for clarification, what harm, if any, could be done to a fully charged battery by leaving it an idle drone for up to three months, say?

And why does the auto-discharge timer reset after a tap on the power button to check the charge level? This would appear to do potentially more harm than good.

Thanks for responding. The Intelligent Flight Batteries are designed to be automatically discharged after a certain period of inactivity to maintain health and longevity. However, over-discharging causes irreparable damage to the battery cell or battery swelling. Furthermore, the auto-discharging is enabled by default and the logic of this process shouldn't affect the performance of it but to increase the battery health. I hope this information helps.

trainee Posted at 12-8 00:36
Not more frequently than once every 10 days anyway… But that's a deduced number and the manual needs to be more specific on this topic.

There you are ... you got an answer that tells you nothing.

Labroides Posted at 12-8 04:15
There you are ... you got an answer that tells you nothing.

Well, it didn't answer my questions but I was interested to learn that "over-discharging causes irreparable damage to the battery". Now I need to know how often qualifies as over-discharging… not that it affects me as my battery holds its charge forever.

trainee Posted at 12-8 04:28
Well, it didn't answer my questions but I was interested to learn that "over-discharging causes irreparable damage to the battery". Now I need to know how often qualifies as over-discharging… not that it affects me as my battery holds its charge forever.

Now I need to know how often qualifies as over-discharging.
It's not how often ... it's how much the battery is discharged.

  I assumed it must be since the manual tells us to do so regularly.
Forget about this ... it's not something you need to do at all unless you are leaving your batteries to sit for months at a time.
The mention in the manual is just about meaningless.
Just make sure that your batteries are fully charged before flying.

trainee Posted at 12-7 03:03
Thanks. Just for clarification, what harm, if any, could be done to a fully charged battery by leaving it an idle drone for up to three months, say?

And why does the auto-discharge timer reset after a tap on the power button to check the charge level? This would appear to do potentially more harm than good.

Mate, I think you have been taken for a ride...

There is no "timer" in any of the BMS DJI batteries...

Nearly 100% of BMS do have 4 primary functions:

1) Cut-off FETs
2) Fuel Gauge Monitor
3) Cell voltage monitor
4) Temperature Monitor

What purpose would a timer serve in a BMS??? Some BMS do have an RTC, but its purpose is to keep track of time, and it cannot be reset...

All the button does is to display to the user the amount of charge left in the battery...

For the BMS to be accurate (Fuel Gauge Monitor), it may take few full cycle (charge/discharge) before it shows the real state of the battery. Keep this in mind..

Also, not all Lipo battery will charge and/or discharge in time to the same level.. Several factors come into play, and it is not just black and white.. If you spend sometime doing some research online, you can find all this information available to you, as these batteries are not just specific to DJI...

There is no harm in leaving the battery in the drone, but it is common knowledge that LIpo battery, given the right conditions and time, can gas up and expand in size...

If a battery expands while inserted in the drone, it can get stuck or even crack the case...

Burt37 Posted at 12-8 16:23
Mate, I think you have been taken for a ride...

There is no "timer" in any of the BMS DJI batteries...

re you saying, "There is no "timer" in any of the BMS DJI batteries.."

then how does its know to discharge to 97%* after 24hrs and how does it know to discharge to 60%* after 9 days?

With regards to the button, You are talking rubbish and misleading a member who is looking for answers.

*figures are estimated as i cannot remember the exact percentage.

DJI Gamora Posted at 12-8 02:55
Thanks for responding. The Intelligent Flight Batteries are designed to be automatically discharged after a certain period of inactivity to maintain health and longevity. However, over-discharging causes irreparable damage to the battery cell or battery swelling. Furthermore, the auto-discharging is enabled by default and the logic of this process shouldn't affect the performance of it but to increase the battery health. I hope this information helps.

Hi Gamora, what happens when the button is pressed once, for example, to check the status of the battery, does this reset the discharge timer?

Bashy Posted at 12-8 18:37
Hi Gamora, what happens when the button is pressed once, for example, to check the status of the battery, does this reset the discharge timer?

This is going to be fun...

I'll wait...

Burt37 Posted at 12-9 00:00
This is going to be fun...

I'll wait...

I am glad you think that, allow me to leave this here...

https://forum.dji.com/forum.php? ... 953&pid=2623271

Bashy Posted at 12-9 04:13
I am glad you think that, allow me to leave this here...

https://forum.dji.com/forum.php?mod=redirect&goto=findpost&ptid=255953&pid=2623271

You do realise that the entire concept of "resets the discharge schedule" is faulty...

So I charge the battery to 100% and after a month (30 days) I press the button once to check the charge, and it should show me maybe 2 maybe 3 LED...

Now according to you because I press the button, I have just reset the discharge schedule. Right?

Reset it to what? To day one when it was 100%? To 30 days after at 60%?

Now obviously you know what you are talking about, so tell me please. What does it reset to?

Burt37 Posted at 12-9 06:20
You do realise that the entire concept of "resets the discharge schedule" is faulty...

So I charge the battery to 100% and after a month (30 days) I press the button once to check the charge, and it should show me maybe 2 maybe 3 LED...

Thats just being dumb, how can it do that, its not a charger lol As i have said through out, it resets the timer, if you cannot get your head around that idea then i cant help you.

All you have to do is do it and prove it to yourself, I will try to spell it out, something like this...

Test 1
Charge battery to 100%
before the following 24hrs has completed, press the button, do this for however long you want before the next 24hrs is up
keep checking the battery and you will see that it will still be 100%, although if you press the butting too many times over x amount of days it may lose 1% or so due to the lights, but doubtful.
After 1 month you will see that if you've been pressing that button before each following 24hrs has completed the battery will still be at 100% or thereabout because each press reset the timer.

Test 2
Charge battery to 100%
wait 30hrs or so then press the button, it will be at around 97%
every do this for the next however long you can be bothered and you will see that the battery will be at 97% because the timer reset at each button press, therefore not allowing it to discharge past 97%

Test 3
Charge battery to 100%
wait 48hrs and see what the battery says, prob be about over 90% still
now, the battery should be discharging to its 60% or what ever it is over the 9 days.
Now keep pressing the button every day and you will see that the discharge will not continue, it will stay at that charge amount until you stop pressing that button daily, once you stop it will then start from day 1 and countdown the 9 days again then carry on the discharge to its 60% unless you press that button before the 9 days is up cause guess what, it will start from day 1 again.

Its a good way to keep the battery at 100% if you are on standby to go out at a moments notice.

For test one, you don't even need to put it in the drone to check the %, after your (however many days you want to try it over) test, stick it on charge, you will see that it will not charge because its still at 100%, unless you let it go over the 24hrs then pressed it.

and now i am bored, i really cannot believe that you did not know this, you been here long enough, its all over this forum, you only have to google, does pressing the button on a dji battery reset the timer or
countdown and you will find no end of it being mentioned.

If you test it anytime after 9 days it resets the timer back to day 1 but it will still be at 60 whatever % it should be at, pressing the button at that percentage wont make much difference, its only whilst the battery is discharging and before it drops to the storage amount of 60 whatever it is is when it will make any difference to the battery state.

Bashy Posted at 12-9 07:20
Thats just being dumb, how can it do that, its not a charger lol As i have said through out, it resets the timer, if you cannot get your head around that idea then i cant help you.

All you have to do is do it and prove it to yourself, I will try to spell it out, something like this...

"Its a good way to keep the battery at 100% if you are on standby to go out at a moments notice."

So this is what you meant by resetting the timer... Now I get it...

Burt37 Posted at 12-9 15:45
"Its a good way to keep the battery at 100% if you are on standby to go out at a moments notice."

So this is what you meant by resetting the timer... Now I get it...

Excellent, the "feature" has its purpose, a good example of its use would be if youre expecting storms sometime during any time during the following days.