Bafang M820 Firmware thread

[borysgo2]

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]

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]

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]

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]

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.