Bafang m820

clix

Active member
Jul 24, 2022
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I also recieved M820 today.

And the same chainring. Whole thing is made from steel, including spider and teeth. It weigths 260g. The matt part is just a plastic cover. It looks to be overmolded.
 

brbr

Active member
Dec 28, 2022
529
270
France
I also recieved M820 today.

And the same chainring. Whole thing is made from steel, including spider and teeth. It weigths 260g. The matt part is just a plastic cover. It looks to be overmolded.
Ahah, thanks for checking! My weak ass magnet was probably confused by the plastic coating 😅
 

brbr

Active member
Dec 28, 2022
529
270
France
I also recieved M820 today.

And the same chainring. Whole thing is made from steel, including spider and teeth. It weigths 260g. The matt part is just a plastic cover. It looks to be overmolded.
We can easily save 100gr by replacing it with that kind of spider I guess: https://www.bike24.fr/produits/417588
Edit: or just use this and save almost 200gr
 
Last edited:

clix

Active member
Jul 24, 2022
186
207
EU
One question:
I received these three motor mounting bolts. One is slightly longer, and two are shorter. Also, there are 3 washers and only 2 thicker spacers. Is this correct? Only 2 thick spacers?
20230619_202427.jpg
 

clix

Active member
Jul 24, 2022
186
207
EU
We can easily save 100gr by replacing it with that kind of spider I guess: https://www.bike24.fr/produits/417588
Edit: or just use this and save almost 200gr
That spider looks reasonably priced. Are you sure, that Bosch gen4 cainrings will fit?
I will probably use the stock one, and change only if I will need different gear range.
 

brbr

Active member
Dec 28, 2022
529
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France
That spider looks reasonably priced. Are you sure, that Bosch gen4 cainrings will fit?
I will probably use the stock one, and change only if I will need different gear range.
I rode a Bosch this weekend and I'd say it's the same offset, but I did not measure anything, only a feeling :)
 

LAnton

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May 12, 2022
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Russia

brbr

Active member
Dec 28, 2022
529
270
France
Guys, anyone has news about the Bafang 43v BTF014 battery ? My Alibaba seller says that bafang does not give them any news ... It's very frustrating.
 

clix

Active member
Jul 24, 2022
186
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EU
Guys, anyone has news about the Bafang 43v BTF014 battery ? My Alibaba seller says that bafang does not give them any news ... It's very frustrating.
Anna Shen from fieldbikes just said to me, that bafang still need more than a month...

We also don't have the frame yet, so yeah... :rolleyes:
 

brbr

Active member
Dec 28, 2022
529
270
France
Anna Shen from fieldbikes just said to me, that bafang still need more than a month...

We also don't have the frame yet, so yeah... :rolleyes:
Frame should be ready verrrrry soon apparently :)
More than a month is bad :(
I have my aliexpress shopping list ready for a 21700 12S1P ultra lightweight pack, I think I'll go for it!
 

clix

Active member
Jul 24, 2022
186
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EU
Unfortunatly, 42V charger won't work. 42V is the max charging voltage of 10s packs, aka 36V nominal packs. You need 12s charger, that will charge up to 50.4V.

For original F014 43V 12s battery, bafang decided to cut charging at 4.1V per cell, so it goes to 49.2, to preserve battery life.

42V is for sure too low, you would be effectively using botton 30-40% of the battery capacity.

Be careful though with the battery pack selection. I wouldn't buy one that doesn't has BMS included, if you are not ready to retrofit one yourself. Also, I would not want to buy prebuilt packs from aliexpress. I have heard, that there are a lot of low quality fake cells/packs there. If I would decide to go DIY, I would buy pack from reputable seller or buy indivudial quality cells (original LG or samsung) from reputable seller and have someone who know what he is doing build it for me, with the quality BMS, ofcourse.

Myself, I will just wait for the official battery.
 

brbr

Active member
Dec 28, 2022
529
270
France
Unfortunatly, 42V charger won't work. 42V is the max charging voltage of 10s packs, aka 36V nominal packs. You need 12s charger, that will charge up to 50.4V.

For original F014 43V 12s battery, bafang decided to cut charging at 4.1V per cell, so it goes to 49.2, to preserve battery life.

42V is for sure too low, you would be effectively using botton 30-40% of the battery capacity.

Be careful though with the battery pack selection. I wouldn't buy one that doesn't has BMS included, if you are not ready to retrofit one yourself. Also, I would not want to buy prebuilt packs from aliexpress. I have heard, that there are a lot of low quality fake cells/packs there. If I would decide to go DIY, I would buy pack from reputable seller or buy indivudial quality cells (original LG or samsung) from reputable seller and have someone who know what he is doing build it for me, with the quality BMS, ofcourse.

Myself, I will just wait for the official battery.
I've found 21700 cells which seems good quality (not on Aliexpress - from an EU store) - LG 4930mAh - 14.4 discharge current - and a 12S BMS on Aliexpress which has good reviews.
I'm still not trusting myself to put this into the frame, if I go with this temporary pack, I'll put this in an external case strapped to the frame.
If my maths are good, 14.4 Amps * 43v = 619 W , if I stay at 50/75% of the assistance, I should be good and not explode the battery :D
 

brbr

Active member
Dec 28, 2022
529
270
France
bad news from Anna Shen : Bafang told them the BTF014 won't be ready before at least 1.5 month ...
that's crazy, no alternative in 43v :(
I honestly don"t know what to do.
Anyone interested in a 43V M820 so I can buy a brand new 36V ? xD
 

brbr

Active member
Dec 28, 2022
529
270
France
Man, this is quite bad ...
Prime riding season here, but the heat is killing me..
still waiting for your frame ? Unfortunately I have too many to do I don't have time to build a DIY battery, I will probably contact someone who does it and pay the extra bucks to get a 12S1P while waiting for the official
 

Dado

Active member
Jun 28, 2022
691
462
Bratislava
bad news from Anna Shen : Bafang told them the BTF014 won't be ready before at least 1.5 month ...
that's crazy, no alternative in 43v :(
I honestly don"t know what to do.
Anyone interested in a 43V M820 so I can buy a brand new 36V ? xD

Mate and what is BTF014?

Anyway I have noticed something with 43V also. Not possible to flash 43V into M510.
They still puting some roadblocks. :(
Time to experiment with flashing also bootloader...
 

brbr

Active member
Dec 28, 2022
529
270
France
Mate and what is BTF014?

Anyway I have noticed something with 43V also. Not possible to flash 43V into M510.
They still puting some roadblocks. :(
Time to experiment with flashing also bootloader...
this is the bafang 43V battery compatible with the m820.
If you can flash the m820 from 43v to 36v, I would be really happy :D but I think these are 2 different hardwares
 

clix

Active member
Jul 24, 2022
186
207
EU
still waiting for your frame ? Unfortunately I have too many to do I don't have time to build a DIY battery, I will probably contact someone who does it and pay the extra bucks to get a 12S1P while waiting for the official
Yes, still waiting. Today I was told, that it should be ready by the end of this month. But I did order custom painting, that will take additional 2-4 weeks..
You already have yours?
 

brbr

Active member
Dec 28, 2022
529
270
France
Yes, still waiting. Today I was told, that it should be ready by the end of this month. But I did order custom painting, that will take additional 2-4 weeks..
You already have yours?
No, still waiting, Jim told me it was supposed to be shipped last week but they were late. Still waiting for news…
I didn’t want custom paint because it was so long! But I won’t have a battery anyway
 

Dado

Active member
Jun 28, 2022
691
462
Bratislava
this is the bafang 43V battery compatible with the m820.
If you can flash the m820 from 43v to 36v, I would be really happy :D but I think these are 2 different hardwares

Not hw, but bootloader is different, which refusing 36 or 48V. Crazy, bafang is making it complicated to themself. Dont understand why they even come up with 43V.
 

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