Bafang m820

[Freda]

Clearly this is a motor to be ridden like a normal bicycle. If you don't put in the work, it wont help you much. I was looking for a light ebike and this is a really good one. It is inspiring you to push full all the time. Since the bike(LCE930) is fairly light it is also fun to ride and easy to move around.

Mostly I have been riding in level 3, but long uphills in boost mode. In technical riding boost feels too much. I have a 720Wh battery so I run out of energy before my bike does, even if several rides have been in cold temperature(-15*C coldest). In summertime I can probably ride more than three hours easy.

I have even thought about changing my battery from 3p to 2p, it would still give me 480Wh and then I could have an additional range extender on 240Wh for long rides. That would remove about 1 kg from the front of the bike, now it feels a little bit front heavy.

If you are looking for full power ebike, or throttle bike, this is not the one to go for.

 

[LAnton]

And soon will be available to use one-up cell battery with new K1 BBR device. (so 43V firmware and 48V battery or 48V and 52V battery)
With good SOC reading and even lower discharge capability - down to 3V per cell.

Has the K1 BBR already been manufactured?

 

[Dado]

Hello Lanton

Almost done. In a code just a small changes to do. Now little problem with testing - cold.
But if somebody wants to become a beta tester, will give a discount.

 

[LAnton]

Hello Lanton

Almost done. In a code just a small changes to do. Now little problem with testing - cold.
But if somebody wants to become a beta tester, will give a discount. View attachment 130985 View attachment 130986 View attachment 130987 View attachment 130988

If there are errors, will it be possible to update the firmware?

 

[Dado]

Hello Lanton.

Good question. Once I pour it with silicon, then not possible to bring microcomputer to bootloader mode and simple copy UF2 file over USB. Usually it is double click on reset.
But there must be a way how to re-flash UF2 only over USB. Will find out, did not try it yet. Will be some simple utility application I guess.
K1 Flash is not waterproof so there is a reset hole on the case.

 

[LAnton]

Hello Lanton.

Good question. Once I pour it with silicon, then not possible to bring microcomputer to bootloader mode and simple copy UF2 file over USB. Usually it is double click on reset.
But there must be a way how to re-flash UF2 only over USB. Will find out, did not try it yet. Will be some simple utility application I guess.
K1 Flash is not waterproof so there is a reset hole on the case.

Hello Dado. I can test with M820 and M560 with 52V voltage

 

[patdam]

hi. question for those who have M820 48V.
Does somebody had power variations at max level on hard climbing (+- 20%) ? I have that on mine. it's lower short variations when i'm upper than 80 rpm. But in cause of these lowering power, i can't keep up 80 RPM. And under, the powerfull lowering are very important and present.
They seem alike those of my first M510, where i needed to replace the torque sensor to solve.

 

[patdam]

"Checked with bafang, bafang said it is normal, when the motor goes hot, the motor has power variations on max power mode."

The answer of linda from SZZS. Really ? we can't use the max power more than 5 seconds ? i have touch the motor to check and i don't find it's hot ?

 

[Freda]

I have the 48V version, but I have not experienced that behaviour. Since it is cold here now I probably don't get overheating issues, even if I have done some testing on full boost and really trying to push as much as possible.

 

[patdam]

I have the 48V version, but I have not experienced that behaviour. Since it is cold here now I probably don't get overheating issues, even if I have done some testing on full boost and really trying to push as much as possible.

Me too, it's +- 10° outside. anyway the motor is not hot when i touch it. I hope that linda will can find helpful competent contact in the bafang company (hard job, i know).

 

[Freda]

Me too, it's +- 10° outside. anyway the motor is not hot when i touch it. I hope that linda will can find helpful competent contact in the bafang company (hard job, i know).

What firmware are you running? I have this one:

Probably doesn't matter, just to check if we have same. GO+ telling me this is the latest..

 

[Freda]

Me too, it's +- 10° outside. anyway the motor is not hot when i touch it. I hope that linda will can find helpful competent contact in the bafang company (hard job, i know).

And everything is relative of course, we have had -30 degrees for the last week in Finland! But coldest have been around -16 when I have been riding.

 

[patdam]

What firmware are you running? I have this one:
View attachment 132073

Probably doesn't matter, just to check if we have same. GO+ telling me this is the latest..

Yes, the same: CRX30PC4809E102007 3_eMTB_230721, i have also tested with CRX30PC4812E102006.3_eRoad_230721. I have not seen differency between the 2. It's not possible that the motor is too hot, it consume 1/2 less than the M510 to more ore less the same performance

 

[patdam]

And everything is relative of course, we have had -30 degrees for the last week in Finland! But coldest have been around -16 when I have been riding.

In this conditions you risk razer to freeze the electrons

 

[patdam]

"Checked with bafang, bafang said it is normal, when the motor goes hot, the motor has power variations on max power mode."

The answer of linda from SZZS. Really ? we can't use the max power more than 5 seconds ? i have touch the motor to check and i don't

Tested in 5 mode. May be every body know that ? but i haven't read it at this time. The max power mode (boost = 100%)would be efficient only for short hard uphill, if you try to use it on long time use, you have motor cuts, even if you don't feel the motor hot, it's seem it's a problemof too hot ? In lower mode (4 = speed+) few power variations in long hard climb (but not really painful). The problem is as you have power limit at 80%, off course that mean less powerfull than 100% and more hard to climb (20%). Really i don't understand those with 700 W who want additional battery ? with climbing all time in mode speed+ i consume 15% to going up 900 m and i'm physically empty

 

[patdam]

Which soft rev do you use ? for those have tried the 2 available (CRX30PC4809E102007 3_eMTB_230721 and CRX30PC4812E102006.3_eRoad_230721) which differncy do you feel ? on which kind of use ?

 

[Dado]

Thats 3A difference, one should feel it.

 

[patdam]

Thats 3A difference, one should feel it.

HI. Me no. It's the reason why i ask if somebody have tested. I'm still interrogate if my motor functioning correctly. Less powerful than M510 is normal, but as it consume nothing, i'm not sure that it provide all it can.

 

[sandnap]

I am just finishing the build on my LCE930 with the 43v 410wh battery and I am having a charging issue. The charger flashes green as it should when it's not plugged into the charging port but when I plug it in it goes solid indicating the battery is full when it is only showing 31%.

Any advice would be greatly appreciated.

 

[mike_kelly]

You battery is a canbus battery. Is your charger a Bafang vbrand charger? How many pin s are in the charging port on the frame?
Here is the manual

https://www.bafang-e.com/uploaded/manual/BF-DM-C-BT%20F014-EN.pdf

 

[brbr]

I am just finishing the build on my LCE930 with the 43v 410wh battery and I am having a charging issue. The charger flashes green as it should when it's not plugged into the charging port but when I plug it in it goes solid indicating the battery is full when it is only showing 31%.

Any advice would be greatly appreciated.

View attachment 133846




View attachment 133849
View attachment 133848

The charging plug is shitty, try to turn it or adjust it. I have the same issue almost at each charge

 

[sandnap]

You battery is a canbus battery. Is your charger a Bafang vbrand charger? How many pin s are in the charging port on the frame?
Here is the manual

https://www.bafang-e.com/uploaded/manual/BF-DM-C-BT%20F014-EN.pdf

Thanks for replying. The pinout in the manual you sent appears to be the same pinout on the charger feildbikes sent, they are both bafang.

Mine

The manual

 

[sandnap]

The charging plug is shitty, try to turn it or adjust it. I have the same issue almost at each charge

Thanks for replying. Wiggled and twisted with no luck.

 

[temon10]

Reach the first 1000km flawlessly.

 

[brbr]

Thanks for replying. Wiggled and twisted with no luck.

That’s too bad, check in the lce930 thread, I think someone had the same issue, it was because of a loose wire in the plug

 

[borysgo2]

Thanks for replying. The pinout in the manual you sent appears to be the same pinout on the charger feildbikes sent, they are both bafang.

Mine

View attachment 133870
The manual

View attachment 133869

I had replaced bafang charging port with standard one. Had a cold solder joint in my plug causing charging issues. There can be one of 3 issues.
1. ID resistor 4.7kR not connected-charger will not provide power.
2. THERMISTOR issue - charger will not provide power.
3. Main cable issue - charger will provide power for 2s and it will cut off due to no current consumption.

I had the issue no3.

 

[Dado]

Interesting, that Bafang used extra pins on charger and used thermistor and ID pin - just complicating things. Would expect rather CAN bus.

 

[mike_kelly]

According to the manual that part number is a canbus battery. There are enough pins extra to be canbus signals, maybe the labels are arbitrary. It is the right part number for the correct charger. The behavior would be indicative of the canbus sensing full when it is not.

 

[Dado]

Yes, is a CAN bus battery, but looks like there is no CAN L/H at charging connector. Can connector is separate.

 

[sandnap]

Thank you all for sharing your knowledge! The canbus connector for the battery comes off of the motor/controller. I wish I would have tested the charger before I mounted the motor covers, cranks, etc.. Oh well, looks like I'll be dropping the motor and checking the connections and charging connector.