I think you need the best tool to change the limit
M820 Bafang - LIGHTCARBON LCE930 Frame (lightweight)
- Thread starter mike_kelly
- Start date
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
and dropping the motor requires dropping the crank arms and the chainring ...
My M820 also has the 43V software, but only goes into error 07 from 54.9V. I'm planning a 13S battery
that's weird... I hope there is no issue with my motor. Tomorrow I'll check the voltage provided by my battery
Yes, it is a 36VSoftware, so you can run with max 46 V
I would prefer to keep the motor and get the 36v battery
Wow, I hope I won't have the same problem, considering seller is the same and so is the time of shipping..
You already have the motor? What’s the serial ?
I just checked. On both stickers it is writen 43v, but there is number 36 in the engraving. Do you have the same?
Yep the same… my friend you need to plug a battery to check!
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?
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
kaylee.s
Member
Mine is exactly the same, and the serial number is only one unit before yours, ends in 61.
No battery yet, so no way to check.
Mine ends in 52
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
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?
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!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 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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