temon10
Well-known member
I change factory setting with besst tools, lowering each assist level.
Bafang m820
- Thread starter Vsoria
- Start date
Please take a photo of the besst settings
M3 12mm, with small washer.
temon10
Well-known member
Waynemarlow
E*POWAH Master
Anybody recommend a supplier of the latest M820 engine, UK bound ?
voigtkampff
Member
LightCarbon has one (LCE086) in their catalog, it's not yet published on their website.
Hi, yes it happened to me recently. The engine was very difficult to turn manually. Error 09 means a problem with the motor phases. I took it apart and after disconnecting the motor connector (3 cables) the motor started to rotate without resistance - therefore the fault of the control unit, shorted mosfet. Now I got a new unit and after connecting the engine runs smoothly. I still have to put the engine back together, but it should be functional again. A new unit costs about 80 euros. But I would like to know where the problem happened. I use a 52V 14s battery and it was charged to 100% 58.8V, the short circuit happened after approx. 100m of going uphill.. Maybe charge at a lower voltage?
So I built a new battery with JBD smart BMS. Charged it to full and did a +2 hour ride on road, mostly Eco mode. Ended up on 78% battery on the display.
Did another ride, without charging, up and down a small hill. Mostly S+ and some Boost mode. I recorded these figures:
I did not wait for battery to stabilize much when taking figures. The BMS seemed to change more up if I let it stabilize between climbs, the display percentage doesn't change much.
Battery saver kicked in at 20% on display. According to GO+, voltage readings were same more or less as BMS voltage readings.
So it seems bms and bafang are counting percentage differently. I don't know waht is correct way. It does suck that battery saver starts when bms is still over 40 % though!
Did another ride, without charging, up and down a small hill. Mostly S+ and some Boost mode. I recorded these figures:
| Minutes | Display | JBD | JBD V | GO+ |
| 0 | 80 % | 72 % | 50.99 V | |
| 23 | 64 % | 62 % | 49.34 V | |
| 42 | 44 % | 52 % | 48.21 V | 48.20 V |
| 52 | 33 % | 48 % | 47.51 V | 47.40 V |
| 57 | 25 % | 45 % | 47.00 V | 47.10 V |
| 69 | 18 % | 40 % | 46.60 V | |
| 85 | 17 % | 35 % | 46.06 V |
I did not wait for battery to stabilize much when taking figures. The BMS seemed to change more up if I let it stabilize between climbs, the display percentage doesn't change much.
Battery saver kicked in at 20% on display. According to GO+, voltage readings were same more or less as BMS voltage readings.
So it seems bms and bafang are counting percentage differently. I don't know waht is correct way. It does suck that battery saver starts when bms is still over 40 % though!
I have exactly the same observations as You - Bafang M820 uses a narrow battery voltage range of 48V (54.6V-46.0V = 100%-20%), which is the equivalent of the voltage for one cell 4.2V-3.54V and most cells can be safely discharge up to 2.5-2.6V (although below 3V it is not very effective). I wonder what voltage range other drives operate in? e.g.: Bafang M510, Shimano, Bosch, Yamaha...
For now, I have fully discharged the 48V 13S3P battery on LG M58T cells for the first time, driving on practically flat terrain (gravel, grass, dirt, forests, meadows) and using the assistance in the percentages E-70%, T-25%, S,S+, B-5%, with my gross weight of about 90 kg and heavy Maxxis DHF tires, I covered 89 km. On Saturday I plan to ride it to the mountains for the first time and I wonder how many kilometers the battery will last
=== EDIT ===
I found a post in which a DADO user also pointed out this with the M510 engine - it looks practically identical to the M820. He also mentions that with the M600 engine, the battery was deeply discharged
LINK
Last edited:
iscander13
Member
Hi, guys. Are there any problems with overruns on this motor. Tried to find info through search, not much info.
what you would mean by "overruns" ?
iscander13
Member
the motor rotates the shaft after the cranks stop for a while.
Last edited:
OK. not on mine. In any case not any for that notice that. i use CRX30PC4812E102006.1 software
I had this on an earlier firmware, 48V eRoad version, but on the eMTB firmwares I have not noticed this or it is only minimal.
What's your current version ?
CRX30PC4812E102006.3_230721
About my firmware (CRX30PC4812E102006.1). in fact it's the 4813 shared by i don't remember who 
. but after upload it's displaying 4812
As i explained here
www.emtbforums.com
. but after upload it's displaying 4812As i explained here
Bafang M820 Firmware thread
Hi All, To make life easier for everyone, post your M820 Firmwares and the relevant details in here.
www.emtbforums.com
Hey all, Looking for some troubleshooting help.
My m820 keeps cutting out. The entire display will reset and sometimes turn back on, sometimes it doesnt. Sometimes the power cuts out midpedal but the display stays on. Its a really weird issue.
I said it has to be a connection issue. So I took the motor out and checked all the connections on the battery and motor. I even tried two different controllers (dpc245 v3.0 and dpc245 v2.0) with the same results. Its very inconsistent and driving me crazy. Sometimes it will work for a few miles, then it will just cut out and not work and wont turn on. Is it possible my battery is bad? Voltage shows its ok. motor is 36v version with 720wh battery.
Looking for any ideas to go with it next. Battery seems good, controllers seem good, connections are all nice and tight... what should i look at next?
My m820 keeps cutting out. The entire display will reset and sometimes turn back on, sometimes it doesnt. Sometimes the power cuts out midpedal but the display stays on. Its a really weird issue.
I said it has to be a connection issue. So I took the motor out and checked all the connections on the battery and motor. I even tried two different controllers (dpc245 v3.0 and dpc245 v2.0) with the same results. Its very inconsistent and driving me crazy. Sometimes it will work for a few miles, then it will just cut out and not work and wont turn on. Is it possible my battery is bad? Voltage shows its ok. motor is 36v version with 720wh battery.
Looking for any ideas to go with it next. Battery seems good, controllers seem good, connections are all nice and tight... what should i look at next?
iscander13
Member
Did you wash your bike the day before? Do you have an on/off button on the frame? Have you tried turning on and pulling the wires with the motor off the frame?
which software rev you use ?
Firmware is in use for this version.
OK you use 43V firmware with 43V battery. If you want to use 48V battery, you does upload an 48V firmware (CRX30PC48...............)
One remark. I suppose that you have bafang battery, that allow to monitoring status of battery and cells on your display. You can't do that with 48V battery.
any of you have this "rocky" mode activated? my will just stay at boost mode.
if have, how you all activate it?
Hi.
I will describe a small experience I had with using two firmware versions in my LEC930 which has a 48V DIY battery installed (13S3P LG 21700 M58T).
1. For the first trip to the mountains with this bike, I had the 48V firmware installed: CRX30PC4812E102006.3 (I didn't notice that it was an eRoad), it rode very well on flat ground, but on uphill sections it was hopeless! the feeling as if the power was being cut all the time, no matter in what mode, and the power seemed to be wavering (sine wave), it did not resemble the support I had ever used before (Shimano, Brose). Overall, I was very disappointed with the engine's performance.
2. Before the second trip to the mountains, I searched the forum, then I noticed that I had the eRoad version installed and additionally I came across a post by user #DADO which concerned the M510 engine and the possibility of uploading software for a lower battery voltage to make greater use of the battery's potential (for 48V firmware - Bafang shows 20% of the remaining battery capacity while its voltage is still ~46V (3.54V per cell, where it could easily be discharged to 3.0V per cell).
Following this path, I uploaded the firmware for 43V: CRX30PC4313E102001.3 (eMTB) and after many tests at home and checking the parameters with BMS software, I found that it looked safe for the engine...
So to the mountains! the route I took was more demanding than the first one and the engine operation was completely different - amazing! it was what I expected from the support and I didn't need any modes other than ECO and TOUR (long years on an analog bike certainly helped) and the climbs were really solid. I will add that the engine warmed up in the same way as before - only checked organoleptically.
So if you have the impression that the engine cuts out power when going uphill, you most likely have eRoad software installed.
If you also want to use the potential of your DIY battery to a greater extent and are aware of the risk of damage, upload the firmware for a lower voltage battery at your own risk.
I will describe a small experience I had with using two firmware versions in my LEC930 which has a 48V DIY battery installed (13S3P LG 21700 M58T).
1. For the first trip to the mountains with this bike, I had the 48V firmware installed: CRX30PC4812E102006.3 (I didn't notice that it was an eRoad), it rode very well on flat ground, but on uphill sections it was hopeless! the feeling as if the power was being cut all the time, no matter in what mode, and the power seemed to be wavering (sine wave), it did not resemble the support I had ever used before (Shimano, Brose). Overall, I was very disappointed with the engine's performance.
2. Before the second trip to the mountains, I searched the forum, then I noticed that I had the eRoad version installed and additionally I came across a post by user #DADO which concerned the M510 engine and the possibility of uploading software for a lower battery voltage to make greater use of the battery's potential (for 48V firmware - Bafang shows 20% of the remaining battery capacity while its voltage is still ~46V (3.54V per cell, where it could easily be discharged to 3.0V per cell).
Following this path, I uploaded the firmware for 43V: CRX30PC4313E102001.3 (eMTB) and after many tests at home and checking the parameters with BMS software, I found that it looked safe for the engine...
So to the mountains! the route I took was more demanding than the first one and the engine operation was completely different - amazing! it was what I expected from the support and I didn't need any modes other than ECO and TOUR (long years on an analog bike certainly helped) and the climbs were really solid. I will add that the engine warmed up in the same way as before - only checked organoleptically.
So if you have the impression that the engine cuts out power when going uphill, you most likely have eRoad software installed.
If you also want to use the potential of your DIY battery to a greater extent and are aware of the risk of damage, upload the firmware for a lower voltage battery at your own risk.
This is interesting. Do you know the upper voltage limit for the 43V firmware? The 48V battery is charging to 54.2V if I remember correctly.
At what voltage is 20% battery according to bafang display? And how low can you go on the battery?
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