Battery mod thread

Justinswidebody · Dec 25, 2019

Switching to non dji battery mode isn't very hard if you have a little computer skills.

Liamjason123 · Dec 25, 2019

I cant wait for a few tutorials on unlocking peramiters ive tried but failed lol

XxRKDOxX · Dec 26, 2019

Justinswidebody said:
I literally have a bms that I just plug batteries into whenever I want. No cells attached at all.

Wanna sell me one of these? lol

Marcuchinonis · Dec 26, 2019

Then, in n

Justinswidebody said:
You have to watch your actual voltage of cells. The mini will sometimes try a forced landing when you still have around 3.5volts per cell... You can stay in the air until it force lands you completely at 3.17volts.

By switching to non dji mode this gets eliminated and you can stay in the air until 2.5volts. However with the added weight the mini has a hard time even hovering after 3volts per cell.

Then, if you are in non dji battery mode, if you can fly until 2,5V, with only the stock battery, maybe you can fly about 30 min?

Justinswidebody · Dec 26, 2019

Marcuchinonis said:
Then, in n

Then, if you are in non dji battery mode, if you can fly until 2,5V, with only the stock battery, maybe you can fly about 30 min?

Yes I can fly 30 min on stock battery

Justinswidebody · Dec 26, 2019

But anafi motors allow me to still have thrust at 2.5v where stock motors do not. So at 2.5v I still have usable power with Anafi motors.

Marcuchinonis · Dec 26, 2019

Justinswidebody said:
But anafi motors allow me to still have thrust at 2.5v where stock motors do not. So at 2.5v I still have usable power with Anafi motors.

Fantàstic. Have you shared Anafi tests anywhere?

Justinswidebody · Dec 26, 2019

Marcuchinonis said:
Fantàstic. Have you shared Anafi tests anywhere?

What kind of test do you want to see?

aeropic · Dec 27, 2019

aeropic said:
[QUOTE="Justinswidebody,
Do you think the 2 data lines are I2C or SPI data and clock lines ? If yes could we spy the bus to reverse ingeeneer the trafic ? The goal being to get rid of the stock BMS coding a kind of stub on a cheap microcontroler....
Well it's good to dream ?

I tried to attach a small logic analyzer to the Clock and data lines of the battery. I succeed decoding the I2C protocol but I'm afraid the step to reverse engineer it is HUGE ...

While not (yet) fried, I think I will stop here and go flying ;-)

Justinswidebody · Dec 28, 2019

aeropic said:
I tried to attach a small logic analyzer to the Clock and data lines of the battery. I succeed decoding the I2C protocol but I'm afraid the step to reverse engineer it is HUGE ...

While not (yet) fried, I think I will stop here and go flying ;-)

So looks too difficult to achieve? Thanks for trying! Wish we had someone who could make a magic board

sooXoo · Dec 28, 2019

if the Chinese haven't succeeded in cloning and selling the BMS, it must be hard

Justinswidebody · Dec 28, 2019

There is someone who has made a bms, but he isn't sharing any details.

sooXoo · Dec 28, 2019

Guess, I missed it somehow... He's either a "good citizen" or already has some bigger plans. Those little boards would sell as hot cakes, at $10 a pop.

exceptional · Dec 28, 2019

Justinswidebody said:
Switching to non dji battery mode isn't very hard if you have a little computer skills.

On 01.00.0200 and 01.00.0300 firmwares it doesn't allow you to change battery_type to 0.

Error: this type has no size

everBit · Dec 28, 2019

sooXoo said:
Guess, I missed it somehow... He's either a "good citizen" or already has some bigger plans

It's 99% that he just reused genuine bms from another battery. Many people just recelling their batts with same or larger capacity cells to not to pay for overpriced DJI ones.

Cloning of new generation DJI's bms (DJI Mavic Air, Mavic 2 Pro, DJI Spark, Mini) at present moment not possible due to special cryptoalgorithm used in communication between Drone and battery which is still not broken.
While there are some knock-ff batteries on the market, they could be used in "non-dji battery" mode only otherwise Drone would not accept them to take-off.

It's continious cat-&-mouse game between OEM and counterfait makers as batteries are big piece of cheese but cats always one step forward because they set the rythm in this overture.

aeropic · Dec 28, 2019

Justinswidebody said:
So looks too difficult to achieve? Thanks for trying! Wish we had someone who could make a magic board

Yes, i think it would be really difficult... If only DJI could release the specifications of the BMS protocol...

mavicn00b · Dec 28, 2019

Can these batteries be re-celled with OTS Samsung 25Rs down the track when the battery wears out ( essentially avoiding DJI tax and re-using the BMS/case)?

Justinswidebody · Dec 28, 2019

mavicn00b said:
Can these batteries be re-celled with OTS Samsung 25Rs down the track when the battery wears out ( essentially avoiding DJI tax and re-using the BMS/case)?

Only if you never did the initial battery update from the initial launched mavic mini.

Justinswidebody · Dec 28, 2019

Here's a 45 min hover test. I love the anafi motors and props!

everBit · Dec 28, 2019

Justinswidebody said:
Only if you never did the initial battery update from the initial launched mavic mini

Some people reported they did it successfully after battery firmware being updated, there is even video on youtube where Mavic Mini user replaced stock cells with Sony 3000mAh ones and did then hover testing.
In comments he confirmed Drone and battery both were updated just upon unboxing (otherwise it was not possible to take-off).