Bafang M820 Firmware thread

[Dado]

First custom firmware for M820 is here.
For now for 11S battery.
The changes introduced in brief:
- fixed battery SOC and cutoff
- fixed walk assist with a lot of more power
- modified SPD Table for more torque sensor range
More details on Endless topic:

"FAKE TAXI Project" - the modified original firmware for Bafang M820 motor

Hi all, I'd like to present a first public version (11.01.2026) of FAKE TAXI firmware for Bafang M820 motor. Link: Proton Drive File: FT_2026_01_11_public.zip SHA256: 60c785e7010da3314eff8d91130a45da5c33051d7e1ef8006375dfe4bfd2f856 Inside the archive, you'll find a readme file with all...

endless-sphere.com

Hello Mdi.

Thats a nice job! How have you done it? Did you code it from scratch?

 

[mdi]

Well it's not my job. I was only consulting, testing and added some features to cannable.
It's not from scratch. It's reverse engineering of original firmware based on version 2.5 and 3.3.

 

[Radolf]

Is this firmware work with 43V motor and battery?

You can check, but first discharge the battery below 46.0V (probably around 55% charge) otherwise your SN number may be lost.

 

[Slaine]

You can check, but first discharge the battery below 46.0V (probably around 55% charge) otherwise your SN number may be lost.

ok, thanks

 

[Dado]

Well it's not my job. I was only consulting, testing and added some features to cannable.
It's not from scratch. It's reverse engineering of original firmware based on version 2.5 and 3.3.

Wow. So you can now update also M560, M510 firmwares? Or soon, right?

 

[mdi]

For now plan is only for M820.

 

[Dado]

Hmmm, why?

 

[mdi]

M820 is much more in need of custom firmware then m510/m560 so focus is on M820.
Also as i sad, i'm not the author so it's not really up to me.

 

[Freda]

First custom firmware for M820 is here.
For now for 11S battery.
The changes introduced in brief:
- fixed battery SOC and cutoff
- fixed walk assist with a lot of more power
- modified SPD Table for more torque sensor range
More details on Endless topic:

"FAKE TAXI Project" - the modified original firmware for Bafang M820 motor

Hi all, I'd like to present a first public version (11.01.2026) of FAKE TAXI firmware for Bafang M820 motor. Link: Proton Drive File: FT_2026_01_11_public.zip SHA256: 60c785e7010da3314eff8d91130a45da5c33051d7e1ef8006375dfe4bfd2f856 Inside the archive, you'll find a readme file with all...

endless-sphere.com

This is really cool! Are there and plans for 13S battery?

 

[mdi]

Yes, there is a plan to battery parameters to be configurable over cannable tool.

 

[temon10]

Yes, there is a plan to battery parameters to be configurable over cannable tool.

how about 10s battery?

 

[maglo18]

You can already use it now, but the battery SoC indicator may show slightly incorrect values.

 

[borysgo2]

Just a small info, the 48V SW:
-CRX30PC4813E102004.3_230214
-CRX30PC4812E102006.1_230216

Are exactly the same.

Regards

 

[parnel bosch gen4]

First custom firmware for M820 is here.
For now for 11S battery.
The changes introduced in brief:
- fixed battery SOC and cutoff
- fixed walk assist with a lot of more power
- modified SPD Table for more torque sensor range
More details on Endless topic:

"FAKE TAXI Project" - the modified original firmware for Bafang M820 motor

Hi all, I'd like to present a first public version (11.01.2026) of FAKE TAXI firmware for Bafang M820 motor. Link: Proton Drive File: FT_2026_01_11_public.zip SHA256: 60c785e7010da3314eff8d91130a45da5c33051d7e1ef8006375dfe4bfd2f856 Inside the archive, you'll find a readme file with all...

endless-sphere.com

Can't wait for 12s !!!!!!!!!!!!!!!!!!!

 

[lkdoido]

Can't wait for 12s !!!!!!!!!!!!!!!!!!!

To change this firmware you will need a new cable (I have the best ones).

 

[Ger@nio63]

To change this firmware you will need a new cable (I have the best ones).

Can you confirm that the fake taxi can be installed with the Best cable?
I have a 36V 720Wh battery. Can I install it?

 

[Radolf]

you can easily install it, but if you have a fully charged battery, the indicator will show less than 100% (FW made for the 11s package)

 

[borysgo2]

Can you confirm that the fake taxi can be installed with the Best cable?
I have a 36V 720Wh battery. Can I install it?

Yes, it goes like a knife into the butter, nice and easy.

Regards

 

[Bozzma]

There seems to be an M820 PRO model now. Can’t find any info on it.

 

[lkdoido]

There seems to be an M820 PRO model now. Can’t find any info on it.

View attachment 174782

I only noticed "PRO" in the text, but I didn't find any difference in the text or body of the engine. I'll ask SZZS about it.

 

[lkdoido]

I only noticed "PRO" in the text, but I didn't find any difference in the text or body of the engine. I'll ask SZZS about it.

Yes. We only added connection ports for external cables; there were no other changes, such as power and torque, which remain the same.

I believe these cable ends will make assembly easier and prevent damage to a connector during assembly; sometimes the simplest things make all the difference.

 

[temon10]

There seems to be an M820 PRO model now. Can’t find any info on it.

View attachment 174782

I hope new version no rattle anymore when downhill

 

[patdam]

I hope new version no rattle anymore when downhill

pas de bruit sur le miens

 

[lkdoido]

There seems to be an M820 PRO model now. Can’t find any info on it.

View attachment 174782

New response:

szzsbike

31 min
@volneicycle Bafang M820 Pro vs Original M820 Core Parameter Comparison

1. Rated Power: 250W (EU/China Standard Compliant) —— 250W (Compliant Value Unchanged)

2. Max Torque: 75-80Nm —— 85Nm (Stronger Climbing/Acceleration)

3. Peak Power: Up to 600W (Boost Mode) —— Up to 600W (Same as Original)

4. Q-Factor: 158mm —— 152mm (More Ergonomic Pedaling, Less Knee Load)

5. Waterproof Rating: IPX6 —— IPX7 (Suitable for Deep Puddles/Heavy Rain, Improved Durability)

6. Energy Conversion Efficiency: Conventional Design —— Optimized Stator & Rotor Design

7. Battery Range: Basic Level —— 10%-15% Improved

8. Heat Dissipation: Basic Magnesium Alloy Casing —— Upgraded Heat Dissipation Structure

Core Upgrade Summary

The core upgrades of M820 Pro focus on torque, pedaling ergonomics, waterproof rating and energy efficiency. The rated/peak power remains compliant with no additional power increase, only optimizing power output and user experience.

 

[mdi]

I do not see Bafang to brag anyware about it. So is this upgrade made by szzsbike ?

 

[Kiwi_Stu]

With 48V battery you should definetly try this 43V firmware. More power and longer range. Downsides are battery percentage is more messed up than normal, it stays on 100% until battery is about 70%, then it drops more rapidly.

Hi Freda, I mentioned to Jean from SZZS that for my 48v battery and motor i wanted to use this 43v firmware as it had been recommended on this forum. Jean said she wasn't sure if it would be ok and is going to check with Bafang but i'm guessing you had no issues? I have the Besst tool ready to go so waiting for any comments here before i pull the trigger and do the install

 

[lkdoido]

Hi Freda, I mentioned to Jean from SZZS that for my 48v battery and motor i wanted to use this 43v firmware as it had been recommended on this forum. Jean said she wasn't sure if it would be ok and is going to check with Bafang but i'm guessing you had no issues? I have the Besst tool ready to go so waiting for any comments here before i pull the trigger and do the install

I have two 48v M820 bikes, but I have firmware for both 48v and 43v. In the 43v firmware, the power only starts to decrease when the battery reaches an estimated 70%, and the assistance cuts off at 12%. I use the 48v firmware and I use conservative power management.

 

[Freda]

Hi Freda, I mentioned to Jean from SZZS that for my 48v battery and motor i wanted to use this 43v firmware as it had been recommended on this forum. Jean said she wasn't sure if it would be ok and is going to check with Bafang but i'm guessing you had no issues? I have the Besst tool ready to go so waiting for any comments here before i pull the trigger and do the install

Well it would be very strange if bafang said it is ok. Then they would just do it themself. I have been running it now already for a long time and it is great. The battery percentage of course is wrong as mentioned, but more power(slightly) and longer range is all good.
I am thinking about trying the fake taxi custom firmware. It solves all problems. Only that would require rebuild or new battery and a new charger.

 

[maglo18]

Well it would be very strange if bafang said it is ok. Then they would just do it themself. I have been running it now already for a long time and it is great. The battery percentage of course is wrong as mentioned, but more power(slightly) and longer range is all good.
I am thinking about trying the fake taxi custom firmware. It solves all problems. Only that would require rebuild or new battery and a new charger.

During the night, test versions of "Fake taxi" for all battery voltages from 10S to 14S appeared. Read the description and choose the right one.

 

[Freda]

During the night, test versions of "Fake taxi" for all battery voltages from 10S to 14S appeared. Read the description and choose the right one.

Thank you for this! I tried the 13S f1 version today with a 48V battery. This was the smooth version. Indeed it is very smooth, very gentle power delivery and almost no override. I will try the other version at some point, but this is how I like it. Very natural feel, needs a lot of rider input to get all the power available. It feels very similar to the 43V version 2004.5 I have been running for a long time already. More natural, but also feels like less power.

I did a 1.5h ride today going from 94% to 20% on the display. It felt like it was dropping too fast, even if I was on boost mode all the time and it was a cold ride, -15 degrees C. I took some screenshots during the ride from my JBD bms app, it was showing different figures. At the start I was at 100% going down to 41% at the end. The percentage showing on the display is not the same as in the graph in the readme file for this firmware. My JBD values are bms stock values, altough they can be configured in the app.

I did not run the battery empty so I cannot comment on performance under 20% yet. And I forgot to test the walk mode.

But all and all this seems like a very good firmware.