It seems to have been discovered that if you leave your Mini 2 Batteries in the Charging Brick or Drone they will not self discharge as they are supposed to do. This can damage your batteries in the long term as they will remain at full charge.

There is a very good video here:



In order to save space in the Bag I have designed a simple little thing that can be printed on a 3D Printer, clipped onto the battery brick and you can then keep your batteries in the brick but they will not be connected. I will upload it to thingyverse and give the thing number here later. Picture attached.

Again, another useful video Ian. Now just to find someone who has a 3d printer to make me one to buy. lol.

The thing number on thingyverse is 4824231 Here is a link that should work.

https://www.thingiverse.com/thing:4824231/files

Enjoy

yogi053 Posted at 4-11 00:40
Again, another useful video Ian. Now just to find someone who has a 3d printer to make me one to buy. lol.

You can buy an Ender 3 Pro 3d Printer from Bangood for about £150 delivered. They are amazing

Bigplumbs Posted at 4-11 00:47
The thing number on thingyverse is 4824231 Here is a link that should work.

https://www.thingiverse.com/thing:4824231/files

Thanks for this,. I was thinking of designing something myself to do this, but yours is perfect. Cheers

Bigplumbs Posted at 4-11 01:07
You can buy an Ender 3 Pro 3d Printer from Bangood for about £150 delivered. They are amazing

Is Banggood OK to use though? I have read quite a few negative reviews on them!

I'm lucky enough to fly almost every day... so never leave them more than a week, but this fault will kill soooooo many batteries...

I'm storing them outside the hub now.

All in all, this is good news, because if you have a flight scheduled the next day after charging, you have 100% energy if you do not take them out of the hub. After the flight, charge the batteries to approx. 75% and then store them comfortably in the hub. It's easy.

djiuser_nO2RdSW5BSUg Posted at 4-11 02:59
All in all, this is good news, because if you have a flight scheduled the next day after charging, you have 100% energy if you do not take them out of the hub. After the flight, charge the batteries to approx. 75% and then store them comfortably in the hub. It's easy.

Alternatively.....a skinny 4 inch wooden skewer and a couple of rubber bands

yogi053 Posted at 4-11 01:17
Is Banggood OK to use though? I have read quite a few negative reviews on them!

I have bought 3 3D Printers from them and all were excellent as was the Service

jweaver Posted at 4-11 01:11
Thanks for this,. I was thinking of designing something myself to do this, but yours is perfect. Cheers

Glad you like it. I love using my printer to solve little issues. Very satisfying

fans9ef7ecdc Posted at 4-11 04:12
Alternatively.....a skinny 4 inch wooden skewer and a couple of rubber bands

Indeed that works also

Bigplumbs Posted at 4-11 05:12
I have bought 3 3D Printers from them and all were excellent as was the Service

Thank you for the info.

Bigplumbs Posted at 4-11 00:47
The thing number on thingyverse is 4824231 Here is a link that should work.

https://www.thingiverse.com/thing:4824231/files

Thank you!  We have 3D printers at the school where I work, but have never tried them.  Now I will!

Well, for $ 23, I prefer to use a chisel to cut a strip in the hub that does not allow the battery to be inserted the other way round. It doesn't protect against anything anyway.

Doesn't it suffice to just not press the batteries down when you insert them in the charging brick? If you don't press them down, they do not make contact (status lights do not come on and you cannot interrogate the battery status using the button on the brick).

Also, does someone have an idea how being connected to the unpowered brick can interfere with the auto-discharge function? Does the firmware inside the battery check for this connection?

fans9ef7ecdc Posted at 4-11 04:12
Alternatively.....a skinny 4 inch wooden skewer and a couple of rubber bands[Image]

Simples....well done.

Herbie53 Posted at 4-11 08:40
Doesn't it suffice to just not press the batteries down when you insert them in the charging brick? If you don't press them down, they do not make contact (status lights do not come on and you cannot interrogate the battery status using the button on the brick).

Also, does someone have an idea how being connected to the unpowered brick can interfere with the auto-discharge function? Does the firmware inside the battery check for this connection?

If you leave them that way is quite easy for them to reconnect, they don't need to be pushed all the way to make contact.

The batteries have a little chip inside so they know if they are connected or not.

djiuser_nO2RdSW5BSUg Posted at 4-11 07:30
Well, for $ 23, I prefer to use a chisel to cut a strip in the hub that does not allow the battery to be inserted the other way round. It doesn't protect against anything anyway.

Does anyone understand that post ?

Herbie53 Posted at 4-11 08:40
Doesn't it suffice to just not press the batteries down when you insert them in the charging brick? If you don't press them down, they do not make contact (status lights do not come on and you cannot interrogate the battery status using the button on the brick).

Also, does someone have an idea how being connected to the unpowered brick can interfere with the auto-discharge function? Does the firmware inside the battery check for this connection?

We are all hoping this can be and will be fixed with a battery firmware update in the future, but as of writing they only discharge if they are not inserted into the drone or the charging hub. So basically the answer is "yes", they know when they are inserted and they don't go through the discharge procedures.

I personally would also recommend active discharging (use the charging hub as a power bank to deplete batteries) instead of waiting for 5 days, especially for the people that live in hot climates.
  
PS: The charging hub is "powered" as soon as a battery is inserted, it does not need to be connected to a charger.

What about the controller? Should that be left to  3 solid lights? Or is it safe to keep it fully charged?

marc70 Posted at 4-11 12:39
What about the controller? Should that be left to  3 solid lights? Or is it safe to keep it fully charged?

I expect they didn't put a LiPo battery in the controller, because the weight is not of great concern. So that will probably be a Lithium-ion battery, suffering much less from being kept at 100% charge.

Herbie53 Posted at 4-11 14:22
I expect they didn't put a LiPo battery in the controller, because the weight is not of great concern. So that will probably be a Lithium-ion battery, suffering much less from being kept at 100% charge.

You would be right on spot! Unless they have changed it for some inexplicable reason (after Mavic Air 2), the controller actually has two 18650 batteries. Being Li-Ion they are way less vulnerable...

Bigplumbs Posted at 4-11 12:21
Does anyone understand that post ?

I think so, the alignment rail causes a friction fit when the batteries are turned around in the hub.
To reduce the friction you can cut down the rail in the hub (the rail fits the groove in the battery when inserted properly).

Not sure about the $23.00 though.

Bigplumbs Posted at 4-11 12:21
Does anyone understand that post ?

Maybe he clicked on the Thingiverse link and saw the $23.00 (22.99) price of the Amazon Basics PLA 3D Filament Spools at the top and thought it was the price of the DJI Mini 2 Battery Saver. Just a guess

Hello there Bigplumbs. Good day and thank you for sharing this information here at DJI Forum. Have a safe and a happy flying always.

"Long-term damage" means what exactly?
How long does it shorten the life of the batteries?

Woah, nice info there to note. Thanks for the share!

ozoffi Posted at 4-11 22:24
"Long-term damage" means what exactly?
How long does it shorten the life of the batteries?

What can happen is the lipos can puff/swell and that would possibly mean that the plastic case would bulge and they may not fit in and out of the drone.

Lipos also just degrade if stored fully charged.

I had a different experience. I left my fully charged batteries in a charging hub for over a month (didn't know better) and I decided to fly my drone on Easter day. To my surprise all of the batteries were pretty much dead (maybe 30% left)
So I think if you leave batteries in the charging hub for some time the battery level goes down.
Don't know if anyone else experienced this

Interesting video!

moniek1996 Posted at 4-12 05:53
I had a different experience. I left my fully charged batteries in a charging hub for over a month (didn't know better) and I decided to fly my drone on Easter day. To my surprise all of the batteries were pretty much dead (maybe 30% left)
So I think if you leave batteries in the charging hub for some time the battery level goes down.
Don't know if anyone else experienced this

Mine were in for 2 months until yesterday.
3 solid lights, 1 was blinking (I did not have time to check the app for the actual status)

Bigplumbs Posted at 4-11 00:47
The thing number on thingyverse is 4824231 Here is a link that should work.

https://www.thingiverse.com/thing:4824231/files

I made it, thanks!!

Thank you for this 3d print, working around a problem that DJI should really fix. The batteries only fit in the bag with the charging hub if in the charging hub. It is clearly how they are meant to be stored by the designers of the bag. I certainly hope this can be fixed by a firmware update and is not a hardware issue.

smbishop Posted at 4-13 11:05
I made it, thanks!!

[view_image]

Glad you printed it fine. It was just a simple little thing I thought about and designed the other morning after watching Ian's video.

It is pleasantly  heart warming to me that some one from the US (Miles) away has now printed and is using my little design.

Just the power of the Internet and 3d printers in a very simple way.

Many thanks for the feedback

Bigplumbs Posted at 4-11 00:47
The thing number on thingyverse is 4824231 Here is a link that should work.

https://www.thingiverse.com/thing:4824231/files

Thanks for that, going to print one tonight and use it until the battery firmware is sorted.

The solution I've settled for is keeping the batteries loose in the top zipper pocket in the carry bag.

Printed a spacer, fits great. Hopefully just temporary until the firmware gets sorted.

Bigplumbs Posted at 4-13 23:31
Glad you printed it fine. It was just a simple little thing I thought about and designed the other morning after watching Ian's video.

It is pleasantly  heart warming to me that some one from the US (Miles) away has now printed and is using my little design.

Forced me to learn how to use the 3D printer at the school I teach at, no one uses it!  Now I have another rabbit hole to dive into learning 3D printing!

Ordered the 3D print linked to above, very happy with it. It fits perfect and does the job. Thanks