M820 Bafang - LIGHTCARBON LCE930 Frame (lightweight)

scm007

Member
Mar 23, 2022
49
3
Seattle
Where do I get that? How did your 1P battery work? So you have 12 * 21700 cells? So what is it ~ 60 WH capacity? What BMS are you using? What I want to do is make battery packs < 100wH (say 6 of them) that I can then fly with. I'm curious how your custom pack is working!
 

brbr

Active member
Dec 28, 2022
529
270
France
Where do I get that? How did your 1P battery work? So you have 12 * 21700 cells? So what is it ~ 60 WH capacity? What BMS are you using? What I want to do is make battery packs < 100wH (say 6 of them) that I can then fly with. I'm curious how your custom pack is working!
you can buy the best tool with your motor reseller, every bafang vendor should have it, you also need an account to use it, they have to give you their account.
My 1P pack has not been tested yet, it's overcharged right now... So I need to discharge it a bit manually (I've connected a resistive charge and I will check in 1h)
It's 12*12700, the cells are 5000mAh, which is 43*5000=215Wh. I'm using a BMS I bought on Aliexpress with dedicated charge and discharge port. You don't find so many 12S BMS but the smart BMS should be able to auto adjust.
If you want to build several smaller battery pack, not sure what you can do, maybe using 18650 cells first, which will be smaller and use a 36V motor.
If you use 2600mAh cells, a 1P pack should be 100Wh. I have no idea tho if it's doable to easily connect all the pack together.
Also, the downtime is quite slim, I think the CEF50 is bulkier, which allows more room for DIY
 

scm007

Member
Mar 23, 2022
49
3
Seattle
Is the internal battery (the 410wh one) removable to recharge off the bike ? Curious about that as I had an orbea rise and the internal battery was super annoying.
 

KaroKönig

Well-known member
Feb 10, 2021
234
506
Germany
I just plugged my battery and I have error 07, it seems it is too high voltage. that's weird, I only have 12 cells, and my motor is 43V... maybe they are overcharged ? but with BMS and dedicated charger, I don't know how that could be possible
My M820 also has the 43V software, but only goes into error 07 from 54.9V. I'm planning a 13S battery
42EA114E-BDE1-429C-963D-14AE889019FC.jpeg
 


clix

Active member
Jul 24, 2022
186
207
EU
Jup, I do. I am not at home right now, but I will check and report back at the beginning of the next week.
 

brbr

Active member
Dec 28, 2022
529
270
France
I had an - not - amazing answer from Anna Shen. She is confused about the motor, and proposed me to sell me the besst tool to check the motor, but nothing more.
No excuse, no proposal to change the motor, no besst tool for free...
 

brbr

Active member
Dec 28, 2022
529
270
France
On my side I bought a 36v BMS that I should receive Tuesday, I will modify my battery and test
 

clix

Active member
Jul 24, 2022
186
207
EU
I don't have a battery yet to test. I do already have a besst tool, but because I don't have a battery, I can't read the firmware version.
Did you recieve any additional feedback from the seller? Is it possible to fix it with the firmware update? Will they be able to provide it?
 

brbr

Active member
Dec 28, 2022
529
270
France
I don't have a battery yet to test. I do already have a besst tool, but because I don't have a battery, I can't read the firmware version.
Did you recieve any additional feedback from the seller? Is it possible to fix it with the firmware update? Will they be able to provide it?
She told me it was possible to update the firmware with besst tool
 

clix

Active member
Jul 24, 2022
186
207
EU
I will maybe go and buy xt30 connector and create a cable, so I can connect it to the lab psu. Will check when can I expect the battery...
 

brbr

Active member
Dec 28, 2022
529
270
France
I will maybe go and buy xt30 connector and create a cable, so I can connect it to the lab psu. Will check when can I expect the battery...
That’s a good idea, you should be able to find an xt30 quite easily. With the besst tool, you should have more details also.
I’ve asked the reseller to send me a btf100 (36v) instead of the btf014, but it’s the same battery case, so there’s also delay
 

clix

Active member
Jul 24, 2022
186
207
EU
Aha. Hopefully, I will be able to acquire a FW, if I will have the same problem. What is concerning to me, is how for M500 and M510 there are multiple FWs floating around. But for M820 there are still none so far. It might be because it is newer motor. I do hope that bafang will stick with it for some time. And possibly introduce a improved version in few years time, so we have an upgrade path. 😁

This battery is taking quite a bit of time already... Did she give you any date? On Thursday Anna said, that there are still some problems, and that it will take few more days... Let's see, if this days, turn into weeks.. Or months....
Other than that, how the bike feels without the battery? Did you ride it around a bit? How did the discharging the battery below the cut off limit go? 🙂
 

brbr

Active member
Dec 28, 2022
529
270
France
Aha. Hopefully, I will be able to acquire a FW, if I will have the same problem. What is concerning to me, is how for M500 and M510 there are multiple FWs floating around. But for M820 there are still none so far. It might be because it is newer motor. I do hope that bafang will stick with it for some time. And possibly introduce a improved version in few years time, so we have an upgrade path. 😁

This battery is taking quite a bit of time already... Did she give you any date? On Thursday Anna said, that there are still some problems, and that it will take few more days... Let's see, if this days, turn into weeks.. Or months....
Other than that, how the bike feels without the battery? Did you ride it around a bit? How did the discharging the battery below the cut off limit go? 🙂
I did a few rides with my 5 year old kid so it was smooth and mellow, but even pedaling up the hills was easy, I didn’t feel I had an ebike without assistance, it just seems it was a normal bike!
I was able to do bunny hops and wheelings so easily, whereas with bigger ebikes (full power bosch), it’s almost impossible to use without assistance.
Regarding the battery discharge, not sure I will be able to discharge it enough to go below the limit…
I’ll remove 2 cells on Tuesday and change my bms, that will be easier
 

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