Bafang M820 Firmware thread

borysgo2

Active member
Feb 1, 2023
121
196
Ireland
Did you notice that you got better range with a 48v battery running 43v firmware since it doesnt cut out as early?
The best way to get better range is use K1 BBR box. It allows the cells to be discharged to 3.0V (2,8V cut off) , which will give easily about 15-20% more range.

The best way to get rid of limp home mode bellow 20% of battery left - install K1 BBR box, press ++-- and in race mode you can have full power to as low as 0%.

Highly recomended.
Regards
 

Dado

Active member
Jun 28, 2022
701
471
Bratislava
The best way to get better range is use K1 BBR box. It allows the cells to be discharged to 3.0V (2,8V cut off) , which will give easily about 15-20% more range.

The best way to get rid of limp home mode bellow 20% of battery left - install K1 BBR box, press ++-- and in race mode you can have full power to as low as 0%.

Highly recomended.
Regards

Thanks a lot. You described the operation better than me. In one sentence. ;)

Yesterday was the first time I did not switch to racing mode. Had 23km in front of me and 28% of batt. ;)

During recent tests I have discovered one little bug. I was charging in a terrain and was looking on percentage, which is misleading. During charging it shows more percent. Which comes from charging voltage and inability to measure charging current. :(
So if you wanna have full battery, then to wait for charger to finish charging. Rather than looking on display awaiting 100%.

There is now BBR Ultimate. For tricking speed and go over 32 kmh and 45kmh with throttle - M510 FC2.0 and M560
 

borysgo2

Active member
Feb 1, 2023
121
196
Ireland
Thanks a lot. You described the operation better than me. In one sentence. ;)

Yesterday was the first time I did not switch to racing mode. Had 23km in front of me and 28% of batt. ;)

During recent tests I have discovered one little bug. I was charging in a terrain and was looking on percentage, which is misleading. During charging it shows more percent. Which comes from charging voltage and inability to measure charging current. :(
So if you wanna have full battery, then to wait for charger to finish charging. Rather than looking on display awaiting 100%.

There is now BBR Ultimate. For tricking speed and go over 32 kmh and 45kmh with throttle - M510 FC2.0 and M560
The battery % while charging will be higher/incorrect due to voltage drop at internal resistance of the cells. To estimate battery % correctly while charging this voltage drop should be subtracted from total voltage. But it is no so important anyway.

Bit of the data:
12s3p battery M58 cells.
100kg rider
1350m elevation
50km distance
25% battery left
MOSTLY S mode an bit of S+ and T
M820 motor
 

Freda

Active member
Feb 5, 2023
168
146
Vaasa
Did you notice that you got better range with a 48v battery running 43v firmware since it doesnt cut out as early?
So I have done two tests. For sure I get more use out of the battery, how much it is in actual use is hard to say. Around 20 percent more or less.

48V firmware goes to limp mode at just under 47V, 43V firmware at around 43V. Percentage shown on the display is even more messed up than before, it stays on 100% until 51V, that is about 70% on the BMS.

This firmware is garbage, I hope I will find a better one for 43V, I don't see any reason to use 48V firmware.

It is a shame bafang have very conservative percentage and add to that a 20 percent limp mode! I don't see any reason for this. This is not the way to save the batteries.
 

Lvtride

Member
Dec 17, 2023
20
14
Vancouver
So I have done two tests. For sure I get more use out of the battery, how much it is in actual use is hard to say. Around 20 percent more or less.

48V firmware goes to limp mode at just under 47V, 43V firmware at around 43V. Percentage shown on the display is even more messed up than before, it stays on 100% until 51V, that is about 70% on the BMS.

This firmware is garbage, I hope I will find a better one for 43V, I don't see any reason to use 48V firmware.

It is a shame bafang have very conservative percentage and add to that a 20 percent limp mode! I don't see any reason for this. This is not the way to save the batteries.
Freda, thank you for testing that. I have been running the 48v firmware and want to get the most capacity front my DIY 48v battery so I'll reflash the 43v firmware. I'll keep an eye out for a new and improved version of the 43v firmware if one becomes available.
 

Pinkee

Member
Jul 5, 2023
15
1
Australia
Hi All,
Firstly, does anyone have the exe file for Besst Pro? Bafangs software page is down and I can't D/L it.

So I had firmware version CRX30PC4812E102006.1 , and decided to update. I first tried CRX30PC4813E102004 (from Freda) which appears to be an earlier version, but while Besst said it was successful, it was still showing the original 4812 firmware. I then tried the later CRX30PC4812E102012.1 (courtesy Tepe) which was successful.
However, This formware has woefully less power output than my original, so I want to either go back to the original firmware or try the 4813. Has anyone managed downgrade the firmware to an earlier version?
 

patdam

Well-known member
Jan 17, 2019
904
601
france
Hi All,
Firstly, does anyone have the exe file for Besst Pro? Bafangs software page is down and I can't D/L it.

So I had firmware version CRX30PC4812E102006.1 , and decided to update. I first tried CRX30PC4813E102004 (from Freda) which appears to be an earlier version, but while Besst said it was successful, it was still showing the original 4812 firmware. I then tried the later CRX30PC4812E102012.1 (courtesy Tepe) which was successful.
However, This formware has woefully less power output than my original, so I want to either go back to the original firmware or try the 4813. Has anyone managed downgrade the firmware to an earlier version?
With BESST tool you can upload all firmware available for you motor. If you can't, that woild mean that it's not adapted at your controler or country rules . bafang develop firmware to answer at request of suppliers. An rev "up to date" would not mean that is better for your use than earlier rev
 

Pinkee

Member
Jul 5, 2023
15
1
Australia
With BESST tool you can upload all firmware available for you motor. If you can't, that woild mean that it's not adapted at your controler or country rules . bafang develop firmware to answer at request of suppliers. An rev "up to date" would not mean that is better for your use than earlier rev
Interesting that they would have restrictions for regions. However I don't think that is the case here (Australia). I will try to install the earlier firmware again and see.
 

patdam

Well-known member
Jan 17, 2019
904
601
france
Interesting that they would have restrictions for regions. However
Not a certainty, It's just my interpretation of fact that i can't download some revision sometime, they correctly upload on the BESST tool, but not to the controler.

When i read the software installed in an new motor, i can see limit speed upper than 25 km/h. But i can't register any modifications if i don't downside limit speed to 25 km/h. I suppose that following country location, you can use or not software dedicated to the motor ?
 

TCFlowClyde

Active member
Feb 26, 2022
1,350
877
Mesa, AZ
The best way to get better range is use K1 BBR box. It allows the cells to be discharged to 3.0V (2,8V cut off) , which will give easily about 15-20% more range.

The best way to get rid of limp home mode bellow 20% of battery left - install K1 BBR box, press ++-- and in race mode you can have full power to as low as 0%.

Highly recomended.
Regards
Do you have a link for the K1 BBR box? I've always hated the 20% reserve mode...sure 10% at most to preserve battery life long-term.😝 Thx
 

Radolf

New Member
May 9, 2024
36
42
Poland
Hello,

I would like to share with You my observations (because they may be useful to someone) from tests of available firmware (FW) for the M820 engine, which are designed for nominal battery voltages of 36V, 43V and 48V. I did all tests on the DIY 13S3P LG21700 M58T battery (nominal 48V) which, depending on the selected FW version, was used in the voltage range:

- FW48V: 54.6V – 46.0V
- FW43V: 54.6V – 42.0V
- FW36V: 46.2V – 38.0V

I only use the bike in the mountains and that is how I tested it riding on the following support modes: T-50%, E-25%, S-25%

ATTENTION!!! If You want to do such tests yourself, do not charge the battery for a specific FW above the voltage indicated above because you will not start the drive (it helps to upload a higher FW in FORCE FLASH mode or discharge the battery using some load).

My observations:

FW48V:
- the power delivered by the engine is highly dependent on the force put into pedaling - it does not resemble the support known to me from Brose, Shimano engines (surprisingly, I have never ridden Bosch in the mountains), when climbing you can feel uneven power delivery - such power fluctuations, there is no problem with dragging the support after finishing pedaling, the minimum power during gentle riding at a speed of approx. 15 km/h delivered by the engine and read from the display indicates approx. 30W for E÷S+ modes, the engine does not heat up as much as in FW36V, in my opinion FW works well in gentle terrain, it is difficult to ride in the mountains.

FW43V:
- the power delivered by the engine is "flat" - it resembles the work of the Brose and Shimano engines I know, you don't feel the wavering power delivered during climbing like with the FW48V, after finishing pedaling the engine can often work for up to about 2 seconds, and in Boost mode when I pressed harder on the pedals it probably worked even longer (this happens randomly and it's hard to say what it depends on), the minimum power delivered by the engine during gentle riding at a speed of about 15 km/h and read from the display indicates about 60W for E÷S+ modes, the engine heats up similarly to when working on the FW48V.

FW36V:
- the power given off by the engine is "flat" practically as noticeable as with the FW43V, after finishing pedaling ONLY A FEW TIMES did the engine work for a moment - max 1 second or maybe even shorter, the minimum power during gentle riding at a speed of approx. 15 km/h given off by the engine and read from the display indicates for E÷S+ modes approx. 50W, I believe that the engine heats up more than when working on FW43V and FW48V (temperature measured organoleptically each time). Unfortunately, I tested this software on the shortest distances of ~20km and climbing max 1000m due to the limitations of the 48V battery in this case - i.e. the narrowest range of possibilities of using its potential.

Conclusion: for me the most refined is FW36V.
Personally, I would like the FW43V to behave the same as the FW36V so that I could continue using my DIY 48V battery to use its large capacity more widely and limit engine heating due to lower currents.
And I am currently facing a dilemma whether to build a new 11s3p battery on LG M58T cells and use the FW36V or wait for the new FW for 43V - 48V to appear... (I would like a real range in the mountains of ~50km/2000UP using only E/T/S modes as before).

I am curious if You have similar observations, especially when using factory batteries?
 

Slaine

Member
Apr 12, 2022
97
39
France
Hello,

I would like to share with You my observations (because they may be useful to someone) from tests of available firmware (FW) for the M820 engine, which are designed for nominal battery voltages of 36V, 43V and 48V. I did all tests on the DIY 13S3P LG21700 M58T battery (nominal 48V) which, depending on the selected FW version, was used in the voltage range:

- FW48V: 54.6V – 46.0V
- FW43V: 54.6V – 42.0V
- FW36V: 46.2V – 38.0V

I only use the bike in the mountains and that is how I tested it riding on the following support modes: T-50%, E-25%, S-25%

ATTENTION!!! If You want to do such tests yourself, do not charge the battery for a specific FW above the voltage indicated above because you will not start the drive (it helps to upload a higher FW in FORCE FLASH mode or discharge the battery using some load).

My observations:

FW48V:
- the power delivered by the engine is highly dependent on the force put into pedaling - it does not resemble the support known to me from Brose, Shimano engines (surprisingly, I have never ridden Bosch in the mountains), when climbing you can feel uneven power delivery - such power fluctuations, there is no problem with dragging the support after finishing pedaling, the minimum power during gentle riding at a speed of approx. 15 km/h delivered by the engine and read from the display indicates approx. 30W for E÷S+ modes, the engine does not heat up as much as in FW36V, in my opinion FW works well in gentle terrain, it is difficult to ride in the mountains.

FW43V:
- the power delivered by the engine is "flat" - it resembles the work of the Brose and Shimano engines I know, you don't feel the wavering power delivered during climbing like with the FW48V, after finishing pedaling the engine can often work for up to about 2 seconds, and in Boost mode when I pressed harder on the pedals it probably worked even longer (this happens randomly and it's hard to say what it depends on), the minimum power delivered by the engine during gentle riding at a speed of about 15 km/h and read from the display indicates about 60W for E÷S+ modes, the engine heats up similarly to when working on the FW48V.

FW36V:
- the power given off by the engine is "flat" practically as noticeable as with the FW43V, after finishing pedaling ONLY A FEW TIMES did the engine work for a moment - max 1 second or maybe even shorter, the minimum power during gentle riding at a speed of approx. 15 km/h given off by the engine and read from the display indicates for E÷S+ modes approx. 50W, I believe that the engine heats up more than when working on FW43V and FW48V (temperature measured organoleptically each time). Unfortunately, I tested this software on the shortest distances of ~20km and climbing max 1000m due to the limitations of the 48V battery in this case - i.e. the narrowest range of possibilities of using its potential.

Conclusion: for me the most refined is FW36V.
Personally, I would like the FW43V to behave the same as the FW36V so that I could continue using my DIY 48V battery to use its large capacity more widely and limit engine heating due to lower currents.
And I am currently facing a dilemma whether to build a new 11s3p battery on LG M58T cells and use the FW36V or wait for the new FW for 43V - 48V to appear... (I would like a real range in the mountains of ~50km/2000UP using only E/T/S modes as before).

I am curious if You have similar observations, especially when using factory batteries?
Hi,

very interesting feedback, I use my M820 with 4310....FW I change my FW with 4313 yesterday. When I make some ride with this FW I write a feedback. I have a Bafang battery
 

aledavi

New Member
Mar 4, 2024
41
3
tarragona
This is bad ,U have less power and road assist characteristic ,get software for mtb then spend 150 usd for besst tool and flash it
hello.

The strange thing is that the seller, LIGHTCARBON, sent me the frame with that motor, since it is the one he needs.
I don't know why I didn't send it with the e-bike version.

Can it only be changed with that tool?

thank you.
 

8Grunf

New Member
Jan 29, 2024
29
101
Italia
Hello,

I would like to share with You my observations (because they may be useful to someone) from tests of available firmware (FW) for the M820 engine, which are designed for nominal battery voltages of 36V, 43V and 48V. I did all tests on the DIY 13S3P LG21700 M58T battery (nominal 48V) which, depending on the selected FW version, was used in the voltage range:

- FW48V: 54.6V – 46.0V
- FW43V: 54.6V – 42.0V
- FW36V: 46.2V – 38.0V

I only use the bike in the mountains and that is how I tested it riding on the following support modes: T-50%, E-25%, S-25%

ATTENTION!!! If You want to do such tests yourself, do not charge the battery for a specific FW above the voltage indicated above because you will not start the drive (it helps to upload a higher FW in FORCE FLASH mode or discharge the battery using some load).

My observations:

FW48V:
- the power delivered by the engine is highly dependent on the force put into pedaling - it does not resemble the support known to me from Brose, Shimano engines (surprisingly, I have never ridden Bosch in the mountains), when climbing you can feel uneven power delivery - such power fluctuations, there is no problem with dragging the support after finishing pedaling, the minimum power during gentle riding at a speed of approx. 15 km/h delivered by the engine and read from the display indicates approx. 30W for E÷S+ modes, the engine does not heat up as much as in FW36V, in my opinion FW works well in gentle terrain, it is difficult to ride in the mountains.

FW43V:
- the power delivered by the engine is "flat" - it resembles the work of the Brose and Shimano engines I know, you don't feel the wavering power delivered during climbing like with the FW48V, after finishing pedaling the engine can often work for up to about 2 seconds, and in Boost mode when I pressed harder on the pedals it probably worked even longer (this happens randomly and it's hard to say what it depends on), the minimum power delivered by the engine during gentle riding at a speed of about 15 km/h and read from the display indicates about 60W for E÷S+ modes, the engine heats up similarly to when working on the FW48V.

FW36V:
- the power given off by the engine is "flat" practically as noticeable as with the FW43V, after finishing pedaling ONLY A FEW TIMES did the engine work for a moment - max 1 second or maybe even shorter, the minimum power during gentle riding at a speed of approx. 15 km/h given off by the engine and read from the display indicates for E÷S+ modes approx. 50W, I believe that the engine heats up more than when working on FW43V and FW48V (temperature measured organoleptically each time). Unfortunately, I tested this software on the shortest distances of ~20km and climbing max 1000m due to the limitations of the 48V battery in this case - i.e. the narrowest range of possibilities of using its potential.

Conclusion: for me the most refined is FW36V.
Personally, I would like the FW43V to behave the same as the FW36V so that I could continue using my DIY 48V battery to use its large capacity more widely and limit engine heating due to lower currents.
And I am currently facing a dilemma whether to build a new 11s3p battery on LG M58T cells and use the FW36V or wait for the new FW for 43V - 48V to appear... (I would like a real range in the mountains of ~50km/2000UP using only E/T/S modes as before).

I am curious if You have similar observations, especially when using factory batteries?

I traveled about 1000 km with a FW43v powered by a 48v battery and I confirm your feelings.
I'm satisfied with it and the overrun doesn't bother me, out of curiosity I was tempted to power the FW43v with a 52v battery but I don't want to cause trouble...
 

DiReCtX

New Member
Apr 24, 2024
10
8
South Poland
Hello,

I would like to share with You my observations (because they may be useful to someone) from tests of available firmware (FW) for the M820 engine, which are designed for nominal battery voltages of 36V, 43V and 48V. I did all tests on the DIY 13S3P LG21700 M58T battery (nominal 48V) which, depending on the selected FW version, was used in the voltage range:

- FW48V: 54.6V – 46.0V
- FW43V: 54.6V – 42.0V
- FW36V: 46.2V – 38.0V

I only use the bike in the mountains and that is how I tested it riding on the following support modes: T-50%, E-25%, S-25%

ATTENTION!!! If You want to do such tests yourself, do not charge the battery for a specific FW above the voltage indicated above because you will not start the drive (it helps to upload a higher FW in FORCE FLASH mode or discharge the battery using some load).

My observations:

FW48V:
- the power delivered by the engine is highly dependent on the force put into pedaling - it does not resemble the support known to me from Brose, Shimano engines (surprisingly, I have never ridden Bosch in the mountains), when climbing you can feel uneven power delivery - such power fluctuations, there is no problem with dragging the support after finishing pedaling, the minimum power during gentle riding at a speed of approx. 15 km/h delivered by the engine and read from the display indicates approx. 30W for E÷S+ modes, the engine does not heat up as much as in FW36V, in my opinion FW works well in gentle terrain, it is difficult to ride in the mountains.

FW43V:
- the power delivered by the engine is "flat" - it resembles the work of the Brose and Shimano engines I know, you don't feel the wavering power delivered during climbing like with the FW48V, after finishing pedaling the engine can often work for up to about 2 seconds, and in Boost mode when I pressed harder on the pedals it probably worked even longer (this happens randomly and it's hard to say what it depends on), the minimum power delivered by the engine during gentle riding at a speed of about 15 km/h and read from the display indicates about 60W for E÷S+ modes, the engine heats up similarly to when working on the FW48V.

FW36V:
- the power given off by the engine is "flat" practically as noticeable as with the FW43V, after finishing pedaling ONLY A FEW TIMES did the engine work for a moment - max 1 second or maybe even shorter, the minimum power during gentle riding at a speed of approx. 15 km/h given off by the engine and read from the display indicates for E÷S+ modes approx. 50W, I believe that the engine heats up more than when working on FW43V and FW48V (temperature measured organoleptically each time). Unfortunately, I tested this software on the shortest distances of ~20km and climbing max 1000m due to the limitations of the 48V battery in this case - i.e. the narrowest range of possibilities of using its potential.

Conclusion: for me the most refined is FW36V.
Personally, I would like the FW43V to behave the same as the FW36V so that I could continue using my DIY 48V battery to use its large capacity more widely and limit engine heating due to lower currents.
And I am currently facing a dilemma whether to build a new 11s3p battery on LG M58T cells and use the FW36V or wait for the new FW for 43V - 48V to appear... (I would like a real range in the mountains of ~50km/2000UP using only E/T/S modes as before).

I am curious if You have similar observations, especially when using factory batteries?
Hi what firmware did you upload for 36V ??

I was going to build batteries for m58lt but there was a chance to have new (not depack) m50lt, I recently did 42km up 1700m and there was 40% of the 720wh/36V battery left in the modes you wrote
 
Last edited:

Radolf

New Member
May 9, 2024
36
42
Poland
I tested on: CRX30PC3615E102003 3_230308
Your mileage/elevation result would be acceptable for me but without any safety buffer, and I think we ride in the same areas - Beskid Śląski/Mały/Żywiecki :)
Unfortunately, I won't fit 10S4P in the LCE frame and I think in the winter I will try to build 11S3P which will give me about 660Wh and on longer trips I will have to adjust a bit to the battery.
 
Last edited:

DiReCtX

New Member
Apr 24, 2024
10
8
South Poland
I tested on: CRX30PC3615E102003 3_230308
Your mileage/elevation result would be acceptable for me but without any safety buffer, and I think we ride in the same areas - Beskid Śląski/Mały/Żywiecki :)
Unfortunately, I won't fit 10S4P in the LCE frame and I think in the winter I will try to build 11S3P which will give me about 660Wh and on longer trips I will have to adjust a bit to the battery.
ok Thanks
I rode this CRX30PC3615E102003 3_230308 firmware, now for a long time I've been using CRX30PC3615E102003.2-CR X30P.250.FC 2.1 somehow I ride better on it in the Beskidy, Żywiecki my favorite :)
 
Last edited:

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