Bought a Mini 2 on the day it was announced, fully charged all the batteries and flew them the next day - down to around 60-70% for storage. Having had lots of DJI drones over the years and having read the plethora of threads and opinions on battery storage, that's what I generally do. Haven't flown it since Nov for a variety of reasons. Pulled out the MM2 battery hub today and noticed that all the batteries have only one solid LED when I hit the power button. I've read the manual and most of the battery threads in these forums, but maybe I missed something.

1. Is it safe to store the MM2 batteries in the hub (no charger connected), or will it discharge the batteries over time?  Couldn't find any reference in the hub manual.
2. I know the MM2 batteries are supposed to auto discharge to 72% - but seeing them down to only one LED bothers me when I left them with at least two. Did they auto-discharge all the way or does hibernation kick in based on storage time? (I know hibernation mode kicks in when the levels drop to 10%, but that shouldn't have happened here...)

Just wondering if I have a problem here. Attempting to charge them all now as I type this and they seem to be charging normally...

Is this normal?
LP

That is not normal, Mine doesn't do that and I have them stored in the hub usually around 55-72%

They are supposed to discharge over 10 days but I haven't tested it but from what I have read on here it doesn't work and they stay almost fully charged even after 10 days.

All 3 of mine have been in the hub unused for around 5 days now and they still have the same charge.

djiuser_hJmrJuQGB6Sn Posted at 1-28 11:37
That is not normal, Mine doesn't do that and I have them stored in the hub usually around 55-72%

They are supposed to discharge over 10 days but I haven't tested it but from what I have read on here it doesn't work and they stay almost fully charged even after 10 days.

Mine stayed the same for several days too.  Then I stopped looking and it's been about 2 months.   Have you let it sit unused for that long?   I'm wondering if they batteries enter hibernation mode after 2 or 3 weeks or something.

LP

LeafPeeper Posted at 1-28 12:12
Mine stayed the same for several days too.  Then I stopped looking and it's been about 2 months.   Have you let it sit unused for that long?   I'm wondering if they batteries enter hibernation mode after 2 or 3 weeks or something.

LP

I haven't left them that long I have only had the drone 2 or 3 weeks but they are supposed to drain a little every day until they reach 72% according to DJI which it is not working apparently and people that are not managing their batteries are going to end up having faulty batteries no thanks to DJI for their products not working as the instructions say.

It doesn’t work for anybody, there are numerous threads on here discussing the issue.  It’s very poor that DJI have not resolved this issue given the potential damage it can cause and the short warranty period extended to batteries.  I’ve not resorted to storing around 54 % manually, as have others.

TDZHDTV Posted at 1-28 13:27
It doesn’t work for anybody, there are numerous threads on here discussing the issue.  It’s very poor that DJI have not resolved this issue given the potential damage it can cause and the short warranty period extended to batteries.  I’ve not resorted to storing around 54 % manually, as have others.

Yeah it is poor really, I was under impression that DJI was untouchable in the drone department so many positives from other people before I purchased the Mini 2.

Android software issues, Hardware not working as intended.

Poor range for me in 2 areas I have now tested.

My 1st impression is not very good.

TDZHDTV Posted at 1-28 13:27
It doesn’t work for anybody, there are numerous threads on here discussing the issue.  It’s very poor that DJI have not resolved this issue given the potential damage it can cause and the short warranty period extended to batteries.  I’ve not resorted to storing around 54 % manually, as have others.

Well clearly I have the opposite problem here - in that my batteries discharged down to one bar....whether that was intended or not.   Not quite sure what is going on here.

LP

djiuser_hJmrJuQGB6Sn Posted at 1-28 13:19
I haven't left them that long I have only had the drone 2 or 3 weeks but they are supposed to drain a little every day until they reach 72% according to DJI which it is not working apparently and people that are not managing their batteries are going to end up having faulty batteries no thanks to DJI for their products not working as the instructions say.

It all works very well with my other DJI drones.    If they're not at about 60% when you put them away, they will start discharging down to 60% after the time you set....and it takes maybe a day or so.   

What I saw here was totally different from what people are complaining about here.   I left them alone for 2 months and they discharged to one bar.  Discharging is fine - but if they're going to do it, they should have discharged down to 3 bars.    I have Mavic Pro batteries that I leave alone for MANY months and when I hit the check button, they haven't budged.

LP

LeafPeeper Posted at 1-28 14:01
It all works very well with my other DJI drones.    If they're not at about 60% when you put them away, they will start discharging down to 60% after the time you set....and it takes maybe a day or so.   

What I saw here was totally different from what people are complaining about here.   I left them alone for 2 months and they discharged to one bar.  Discharging is fine - but if they're going to do it, they should have discharged down to 3 bars.    I have Mavic Pro batteries that I leave alone for MANY months and when I hit the check button, they haven't budged.

Yeah that should not be happening, Have you updated the firmware for the batteries?

I got the fly more combo and for some reason I only got the firmware notification for 2 out of the 3 batteries and I can't check what version they are because for some reason the software is dumb and tells you the Drone firmware the RC firmware and the fly database.

You would think something as important as the batteries we would have the correct information.

As it stands I have no idea if 1 of the batteries has the latest firmware or not.

If they are discharging to 1 bar they will fail sooner I imagine.

Send them off to DJI if still in warranty.

djiuser_hJmrJuQGB6Sn Posted at 1-28 15:45
Yeah that should not be happening, Have you updated the firmware for the batteries?

I got the fly more combo and for some reason I only got the firmware notification for 2 out of the 3 batteries and I can't check what version they are because for some reason the software is dumb and tells you the Drone firmware the RC firmware and the fly database.

I was going to ask if the M2 batteries even had firmware, or if they are "non-smart".  I updated all the firmware today, but didn't get any battery notices.

Now wondering if my hub is bad.  It's cheap enough to buy another.

LeafPeeper Posted at 1-28 16:24
I was going to ask if the M2 batteries even had firmware, or if they are "non-smart".  I updated all the firmware today, but didn't get any battery notices.

Now wondering if my hub is bad.  It's cheap enough to buy another.

Well it looks like ONE battery had downlevel firmware.   Not sure why it didn't upgrade the last time I flew - especially since the other two apparently didn't need to be upgraded.

Can anyone from DJI confirm that the behavior I observed (all batteries depleted to one LED when stored in the charging hub for an extended period of time without power) would be expected from mismatched battery firmware?   Is there any reason to believe it damaged the batteries?   Or do I have a defective hub?

Thanks for any help,
LP

So far the lowest my batteries go is 97% after a day or two and 95% after just over a week or two.

I'm having a similar experience. I have just one Mini 2 battery and it never discharged automatically. I have left it untouched for at least 10 days and it is still at 4 lights.

Hello there LP. Thank you for reaching out and for these information you have given. In addition, you can use the DJI Mini 2 Two-Way Charging Hub to store your DJI Mini 2 Intelligent Flight Batteries. Just a reminder that the battery's performance will be influenced if it is kept idle for a long time. To maintain the battery's active state, it is recommended that users charge and discharge the battery every three months. Do not completely discharge the battery and then store it for a long time; otherwise, the battery will over-discharge and the battery cells will be damaged, which will make the battery unusable. For reference, I will be posting a link where in you can see the manual of the DJI Mini 2 Two-Way Charging Hub ( https://dl.djicdn.com/downloads/ ... _Hub_User_Guide.pdf ). Thank you.

LeafPeeper Posted at 1-28 16:24
I was going to ask if the M2 batteries even had firmware, or if they are "non-smart".  I updated all the firmware today, but didn't get any battery notices.

Now wondering if my hub is bad.  It's cheap enough to buy another.

Yeah they do, I did not even realise they needed a firmware update only because of this forum, Have to wait a little while on the DJI fly screen before pressing go fly.

I still do not know how to check and why I have only had 2 batteries get the firmware notification and more to the point IF 1 was already updated in my combo pack why did DJI in the 1st place not update all?

So I am still unaware how to check the version numbers on the batteries.

GaryDoug Posted at 1-28 19:24
I'm having a similar experience. I have just one Mini 2 battery and it never discharged automatically. I have left it untouched for at least 10 days and it is still at 4 lights.

This is not a similar problem.  My post is about the batteries discharging TOO FAR.

DJI Stephen Posted at 1-28 20:53
Hello there LP. Thank you for reaching out and for these information you have given. In addition, you can use the DJI Mini 2 Two-Way Charging Hub to store your DJI Mini 2 Intelligent Flight Batteries. Just a reminder that the battery's performance will be influenced if it is kept idle for a long time. To maintain the battery's active state, it is recommended that users charge and discharge the battery every three months. Do not completely discharge the battery and then store it for a long time; otherwise, the battery will over-discharge and the battery cells will be damaged, which will make the battery unusable. For reference, I will be posting a link where in you can see the manual of the DJI Mini 2 Two-Way Charging Hub ( https://dl.djicdn.com/downloads/DJI_Mini_2/Accessories/DJI_Mini_2_Two-Way_Charging_Hub_User_Guide.pdf ). Thank you.

Thanks Stephen - but my issue is that I put the batteries away with 3 LEDs each, left them for 2 months and came back to 1 LED each.   This wasn't about me discharging the batteries and storing them that way.   The manual didn's say anything about the hub completely discharging the batteries like this.   It was nothing *I* did.   Do I have a warranty issue here?

LeafPeeper Posted at 1-29 04:51
This is not a similar problem.  My post is about the batteries discharging TOO FAR.

I was responding to the post above mine, not yours.

djiuser_hJmrJuQGB6Sn Posted at 1-28 23:08
Yeah they do, I did not even realise they needed a firmware update only because of this forum, Have to wait a little while on the DJI fly screen before pressing go fly.

I still do not know how to check and why I have only had 2 batteries get the firmware notification and more to the point IF 1 was already updated in my combo pack why did DJI in the 1st place not update all?

Current belief is when you update the firmware of the drone that automatically updates the firmware of the battery.

Only when you put other batteries in and wait on the home screen do you get to update the others. For me one worked, the other it started but the app stopped updating the progress bar, but drone turned off. So assumed it did it.

Just checked my batteries. Two in the charger taken out and checked in the AC, readings of 96%. Battery in the AC originally, checked and sitting at 75%, same as when ceased flying 2 weeks ago.
In conclusion, battery charge states not changed after 2 week period. All batteries dated 10/20.  Just for information.

yogi053 Posted at 1-30 03:26
Just checked my batteries. Two in the charger taken out and checked in the AC, readings of 96%. Battery in the AC originally, checked and sitting at 75%, same as when ceased flying 2 weeks ago.
In conclusion, battery charge states not changed after 2 week period. All batteries dated 10/20.  Just for information.

I think part of the reason I'm not getting any clear answers is because very few people have bought the Mini 2 and let it sit in storage for 2 months, just 3 months after announce.  Most people are out flying them.  I checked my battery levels for a few weeks after I got it too - and they didn't budge....so I stopped checking.  Fast forward to a week ago and they were depleted.  We're likely talking about a slow degrade here.

LP

Just checked my batteries.

Bought MM2 early in Jan 2021. Only charged the battery that was in the drone. Updated firmware and did a test flight of about 5 mins.

Due to lockdown restrictions I haven't used it since.

Today the battery in the MM2 was still showing 4 light and the two that came with the flymore pack showed 1 light. They have not been charged previously.

I have now updated the firmware on those too.

Should I fully charge the two unused batteries or only take them to 3 lights?

Skynet5 Posted at 1-29 12:51
Current belief is when you update the firmware of the drone that automatically updates the firmware of the battery.

Only when you put other batteries in and wait on the home screen do you get to update the others. For me one worked, the other it started but the app stopped updating the progress bar, but drone turned off. So assumed it did it.

Right I see, So when the 1st battery was in it updated the firmware of the drone and that batter at the same time, I did not get a notification about that battery but if that was tied into the 1st drone firmware that makes sense thanks.

Yep...  I bought a Mini 2 in late May and charged up the two batteries I got with it and intended to give it a spin that weekend, but life got in that way and I just recently got back to it (mid-Oct), but I was surprised to see the batteries at around 25%!  I wasn't aware of the auto-discharge at the time, but it seems to me that the circuitry could be drawing a small amount over the long-term and if there's no lower-limit, it could easily destroy the batteries in long-term (6 months?) of storage!

Also, Li-Po self-discharge is nowhere near that fast, so the nonsense about "charging every three months..." is just cover for a BMS system that has a small vampire drain and will inevitably destroy the battery if left in long-term storage, say 6-9 months.  Not great...