Bafang M820 Firmware thread

[borysgo2]

Freda
Did you fitt 13S3P battery into the lce930 frame ??

I have done 12S3P and all the battery stuff fits in between the mounting holes. So another 70mm in theory will fit, but it would be very tight.

THX
Peter

 

[Freda]

Freda
Did you fitt 13S3P battery into the lce930 frame ??

I have done 12S3P and all the battery stuff fits in between the mounting holes. So another 70mm in theory will fit, but it would be very tight.

THX
Peter

Yes I did, I believe it is maximum. Since this picture I did rebuild it so I now have plastic M6 screws and metal counterpart on battery. Also added a handle to pull it out, since I made it very tight so everything would stay in place. So far has been working very well.
I would make a 13S2P shorter using the second holes for attaching it, it would be about 14-15 cm shorter.

 

[PaulH]

Yes I did, I believe it is maximum. Since this picture I did rebuild it so I now have plastic M6 screws and metal counterpart on battery. Also added a handle to pull it out, since I made it very tight so everything would stay in place. So far has been working very well.
I would make a 13S2P shorter using the second holes for attaching it, it would be about 14-15 cm shorter.
View attachment 140362

Very nice job Freda, Bafang should hire you as a consultant or something.

 

[Freda]

Very nice job Freda, Bafang should hire you as a consultant or something.

Thank you, but I am only a happy amateur, trying to get the best out of what I have.

 

[temon10]

Yes I did, I believe it is maximum. Since this picture I did rebuild it so I now have plastic M6 screws and metal counterpart on battery. Also added a handle to pull it out, since I made it very tight so everything would stay in place. So far has been working very well.
I would make a 13S2P shorter using the second holes for attaching it, it would be about 14-15 cm shorter.
View attachment 140362

DId U make 3D printing for this battery holder?

 

[Freda]

DId U make 3D printing for this battery holder?

For the present 21700 cells I used this, M6 size. I glued and taped the aluminum square nut in place on the battery. And plastic M6 screws. I have cellofoam around the cells to make it a tight fit. It doesn't move at all, even without the screws. That is why I needed a handle to pull it out.

For a 18650 cell battery, normal brackets fit in the frame: Bracket

 

[ficorama]

as per the good old custom, the bafang firmware is a disaster in terms of battery percentage. I went to check the battery voltage when it was 20%. voltage is 36V. horror, with the firmware I use and a 10s battery, the range is 30km and 1500m altitude. battery is 10s 21700 cells LG58t, 17.4ah. below 70% the percentage drops rapidly in percentages of 5-10%. it doesn't show on the screen that it drops by 1%, well done Bafang!

 

[voigtkampff]

below 70% the percentage drops rapidly in percentages of 5-10%. it doesn't show on the screen that it drops by 1%, well done Bafang!

I have a similar effect. It seems like the controller is unable to take battery level measurements as long as I'm pedaling uphill and engine is running. During the ascent battery level stays constant, only after I stop pedaling I see a sudden battery percentage drop by 5-10%. Is this the same with you?

 

[ficorama]

I have a similar effect. It seems like the controller is unable to take battery level measurements as long as I'm pedaling uphill and engine is running. During the ascent battery level stays constant, only after I stop pedaling I see a sudden battery percentage drop by 5-10%. Is this the same with you?

the same thing happens to me!
the firmware is like that!
on the m500, m510 and m820, program the firmware to reduce the power to 30%. What do they protect with that voltage?
according to the man who works the batteries for me, they protect the controller-motor because if the voltage is too low, the components heat up more.

it is not clear to me that it shows 20% at 36V! 36V is the nominal voltage of the battery, my battery is 17.4A 625wh, according to the bafang firmware the battery is approx. 400wh!

Normally batteries work from 30v to 42v. at 30v turns off bms. that means it works between approx. 32v and 42v. the bafang firmware probably works between 34-35v and 42v.
where a lot of battery capacity is lost.

 

[Freda]

I have a similar effect. It seems like the controller is unable to take battery level measurements as long as I'm pedaling uphill and engine is running. During the ascent battery level stays constant, only after I stop pedaling I see a sudden battery percentage drop by 5-10%. Is this the same with you?

I haven't measured voltage, but it feels that percentage drops quickly down to 90, then slowly to 60-70 and after that big drops down to 20%. Under 20% seems to last forever, but that can be thanks to very low assistance.

 

[aledavi]

Hello

I'm riding an LCE930 electric bike.
The motor that came to me is the Bafang M820.43v.
On the engine label it gives me this number:
CRX30PC4310E102001.5

What can you tell me about the engine with that number?

greetings

 

[Waynemarlow]

Normally batteries work from 30v to 42v. at 30v turns off bms. that means it works between approx. 32v and 42v. the bafang firmware probably works between 34-35v and 42v.
where a lot of battery capacity is lost.

The last couple of volts only equates to about 10% of the total Wh available. Bafang obviously don’t want to stress their batteries life span by going down to completely emptying the cells. It makes good commercial sense when a large percentage of their clients are commuters rather than a few EMtbers.

In my view to get that last 10% then the options are pretty limited. About the only option we have is the BB Racing device BB Racing – K1 eBikes – Bafang Tuning and Services, it seems to work well and will allow 52 volt batteries to be used.

 

[ficorama]

DId U make 3D printing for this battery holder?

Hello. what bms are you using in the batteries?

 

[temon10]

Hello. what bms are you using in the batteries?

cheap 10s bms from aliexpress