Battery mod thread

[lalanomana]

Hi guys, this is my 1st post here and btw, I send you greetings from France for this new year.

... And I have a question : Is there anyone here who could extract a working battery memory dump ?
The goal is to retrieve an original firmware to re-flash new batteries with old firmware.

The old battery firmware is hard to get, but i think for the new battery firmware, you just need to get an "not updated battery" and do a update with android phone, when the DJI Fly app downloaded the firmware, just right before it starts the update, quickly pull out the battery from your drone, and go into the temporary folder and look for the downloaded "new battery firmware"... Hope it helps..

 

[sooXoo]

$50 iPhones are sold at $500 so DJI is not first in this 'invention'.
But they still allow to use $3 cells in their batteies by selecting 'non-dji battery' option in the engineering settings.
With loss of any warranty but customers at least still have an option.

Is this already available for MM? How do I get it work?

 

[everBit]

Yes, have you read this thread from the beginning?
It has proofs of successfull cells replacement. There is a link also to the video guide on how to do that.
Page 4 has hints on how to select "non-dji battery" in the settings.

 

[sooXoo]

Thanks, missed that...

 

[ioman]

Hey, I have logical analyser at home, I will try to analyse the data communication between the battery and the drone and think if it could be replicated with custom chip.

 

[everBit]

but i think for the new battery firmware, you just need to get an "not updated battery" and do a update with android phone,

There is not much benefits of getting the new battery firmware as it has been patched by DJI.
The most valuable is so called "magic" release, i.e. initial v100 one.

@ioman
Have you looked here? The first half of your idea already done by aerop, the second one is still quite hard nut even for chinese reverse engineering industry.

 

[aeropic]

Hey, I have logical analyser at home, I will try to analyse the data communication between the battery and the drone and think if it could be replicated with custom chip.

Hello, I tried this (see some posts above) without a lot of success... I mean the I2C protocol has been logged but reverse-engineering it seems quite a difficult task !
Here is what I got...
For your information, attaching two wires to SDA and SCL pins of the batt is quite easy and I found the ground on the shielding of the microUSB port : just connect the USB A--µSD wire charging wire and grip the USB A socket to get an easy ground ;-)
I am very interested in your results...

 

[Marcuchinonis]

[QUOTE = "aeropic, post: 901671, miembro: 112118"]
Hola, probé esto (ver algunas publicaciones anteriores) sin mucho éxito ... Quiero decir que el protocolo I2C se ha registrado, pero la ingeniería inversa parece una tarea bastante difícil.
Esto es lo que obtuve ...
Para su información, conectar dos cables a los pines SDA y SCL del bloque es bastante fácil y encontré la tierra en el blindaje del puerto microUSB: solo conecte el cable de carga USB A - µSD y agarre el enchufe USB A para obtener un terreno fácil ;-)
Estoy muy interesado en tus resultados ...
[/CITAR]
Hello. What’s the utility for connecting Sda, scl and ground ?

 

[aeropic]

Hello. What’s the utility for connecting Sda, scl and ground ?

To place a logic analyser on the i2c bus between MM esc board and BMS in order to try to understand the exchanges between those two board with the secret hope to emulate the BMS behavior on a 'magic' board !

 

[Marcuchinonis]

Hola. Qué piensas sobre esto

FancyWhoop Batería de 3500mAh 7.6V 2S LiPo LiHv con Enchufe XT30 para el Controlador Remoto del Transmisor Frsky ACCST Taranis Q X7: Amazon.es: Electrónica

FancyWhoop Batería de 3500mAh 7.6V 2S LiPo LiHv con Enchufe XT30 para el Controlador Remoto del Transmisor Frsky ACCST Taranis Q X7: Amazon.es: Electrónica

www.amazon.es

 

[Justinswidebody]

Hola. Qué piensas sobre esto

FancyWhoop Batería de 3500mAh 7.6V 2S LiPo LiHv con Enchufe XT30 para el Controlador Remoto del Transmisor Frsky ACCST Taranis Q X7: Amazon.es: Electrónica

FancyWhoop Batería de 3500mAh 7.6V 2S LiPo LiHv con Enchufe XT30 para el Controlador Remoto del Transmisor Frsky ACCST Taranis Q X7: Amazon.es: Electrónica

www.amazon.es

This battery will not work good for the mini.. I have it. The C rating is not high enough. It last only 5 min.

 

[Ivan_LCF_666]

These are Lion batteries. Not LiPo batteries. They have different chemistries and different voltage ranges. The big advantage to using Lion is that they can be stored on full charge indefinately and can be discharged to 0 without significant damage unlike LiPos. Their only downside is that they cannot supply the same high current that a LiPo can. But in the case of this lightweight drone, current supply is not a big issue.

Really?

So its OK for my Mavic Mini to be fully charged during the night and then if I skip the next day and don't fly and only fly after like 48 hours my battery will be all perfectly fine?

I like to charge my Mini at night, like from 23:00 to 2:00 because I like to slow charge my battery as to preserve it. Sometimes though I don't get to fly the next day. Hopefully my sweet Mavic Mini's battery will be OK like that. Else I'm looking to buy another 2 Mavic Mini batteries so that I have 3 altogether - they just seem to not have any in stock anywhere!

Sweet

PS: I'm gonna not keep my Mavic Mini's battery charged fully for over 3 days ever, I just hope that 48 hours is OK to be fully charged.

 

[RogerDH]

The battery mod I'd like to see would be a case that allows easily replacing the 18650s. I wonder if DJI would sue anyone who made something like that? (Asking for a friend...)

 

[netsonic]

I saw the latest video from "Fly Far and Wide" on Youtube, where he landed the mini over 14 km away from the home point. The interesting thing is how the craft looks like with the modded battery as he did mod the belly and rear of the drone to accommodate the extra batteries. I also looked at a previous video where the case was still intact (belly + rear) and posted pictures below.

It looks like the Mini has a Stock battery or at least the electronics (Magic board) and on each side he strapped two 2S LiPo's.
Found this info in the comments 1 x 1100mAh, 2 x 1480mAh

Pictures below from this video

And from this video

 

[everBit]

He posted in comments that this mod is based on stock DJI MM Japanese version battery and extra cells from Spark drone battery.

The Japanese variant uses 4.40 LiHV cells instead of 4.2V 18650 ones. So it would accept extra cells of similar HV chemistry. But without bms reconfiguration at firmware level it would wrongly calculate charge percentage and estimated flight time while still correctly reporting all other telemetry like cells voltages etc.

If one noticed throughthout all the flight the charge level remained at 0%.

ps.
the distance passed was much more then 14km, it's about 22km!

 

[netsonic]

Thank you @everBit ! You are spot on, found the info in the comments and added it above.

 

[everBit]

Just subscribed to his channel, so have looked the video as soon as it was released yesterday yet

 

[Mavic_Mini_Pilot]

I'm looking to buy me some of those cool cells that you're using to get those 40 minutes flights times! For me 40 minutes will be really awesome! The problem is that currently I want to buy me another original, real 2 intelligent flight batteries for my Mavic Mini & I can't seem to find any at all. I'm from Bulgaria so US shops aren't really preferable for me, Europe on the other hand is the way to go.

I will buy me another 3-rd brand new intelligent-flight drone battery and take that apart (after a few normal flights maybe) to put the new cells inside! I really really REALLY want to achieve what you're done with you re power system for the Mini! I want to "edit" the drone's battery so that it looks and feels exactly the same as a normal, original battery - only difference will be it will have a bigger mah capacity and fly for over 40 mins! It's important for me that the drone looks unmodified and all normal during flights - and that the battery looks all normal - like I said only difference I want is the charge capacity increase.

So please point me (share link) to the Li-Ion cells that you use and also to some normal, original if possible, DJI Mavic Mini intelligent flight batteries...

Thanks in advance everyone, happy flying our Minis!!!

 

[netsonic]

I want to "edit" the drone's battery so that it looks and feels exactly the same as a normal, original battery - only difference will be it will have a bigger mah capacity and fly for over 40 mins!

If you want to do this, read this thread from the beginning. You can achieve it as Justin did, keeping it looking stock, however you need to exchange the motors with ones from Parrot Anafi + Anafi propellers and then combine this with bigger batteries. Just read as all info is present here, 40 Min flight time is doable.

 

[Mavic_Mini_Pilot]

I really really would like to buy me another 2 Mavic Mini Intelligent Batteries guys! I'm located in Bulgaria as you all can probably see - in all the shops I get a "we're waiting for new stock to arrive"! So now I'm willing to order me the 2 maybe even 3 I'll gets from outside my country. Not sure where from, but will have a look around online. It's amazing hey, its not like I'masking for some super special product or something, just wanna have me 4 normal Mini batteries so I get en easy hour and a bit over in the air - yeah 4 will do it sweetly - around 90 minutes I'll be super happy.

Now I fly my single battery and that's it, gotta wait for it to charge for like 50 minutes after that.

Hopefully someone will point me to a place that will promptly gets me my 2 or 3 new batteries.