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YamBMS JK-BMS-CAN with new Cut-Off Charging Logic (open-source)
- Thread starter Sleeper85
- Start date
ScrotpusGobbleBottom
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Badger the solar
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- Oct 19, 2020
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Which Deye and what pins?
bmsmanualneed
New Member
JKBMS B2A20S20P
BLE
I mean balancing, not equalizing.
Sorry I could have described the entity better.
PS The status is good now. I'll be watching.
Today a friend come with hes JK BMS that had broken the + wire of GPS port and probbably made a short to GND. The issue was temperature probes T1 and T2 was reading -41 forcing BMS to trip Under Temp Protection and faulty communication (ESP was reporting wrong data: Bat voltage 600V...and some strange values for other parameters).
The GND of GPS port is connected to B- trough a 200ohm resistor that was burned by +Vbat wire of GPS port shorthing to GNG of GPS port and act like a fuse. (See attached picture, GPS port has connector with wires attached ). The temperature probes T1 and T2 share the same GND as GPS port trough the 200ohm resistor, they are not connected to B- directly.
In this case the issue was not related to power supply but not using an isolated power supply can lead to this kind of problems.
I was able to fix the BMS but i wanted to share my experience here.
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Three phase 12kw Deye. The 12V is available on internal CN2 connector between pin 7-8.
Yes. I have edited the post. Thanks!Guess you meant B-
@Sleeper85 What to do with "the equation", k=0.05 etcetera, for newer LFP cells like Eve MB31 or Rept CB75?
These newer MB31 and CB75 datasheets do no longer contain a 0.05C termination current. Instead these LiFePo4-cells stop standard charging mode with 0.5P at 3.65V. 0.5P is 502,4W for the MB31. Thus current at 3.65V will be approximately 137,6 Amps. Nominal capacity = 314Ah, thus charge termination is at approximately 0,438C.
This feels like charging is stopped a lot earlier with the newer MB31/CB75 cells compared to for example an LF280K, where charging stopped when the current was dropped to only 14 Amps (0.05C) at the same 3.65 volts.
These newer MB31 and CB75 datasheets do no longer contain a 0.05C termination current. Instead these LiFePo4-cells stop standard charging mode with 0.5P at 3.65V. 0.5P is 502,4W for the MB31. Thus current at 3.65V will be approximately 137,6 Amps. Nominal capacity = 314Ah, thus charge termination is at approximately 0,438C.
This feels like charging is stopped a lot earlier with the newer MB31/CB75 cells compared to for example an LF280K, where charging stopped when the current was dropped to only 14 Amps (0.05C) at the same 3.65 volts.
bmsmanualneed
New Member
I have a question for the Author: Is there a place where the operation of individual settings is explained? I would like to better understand how YamBMS works. I’m not referring to block diagrams but rather descriptions of how entities function, where I can set voltages or percentages.
My friend uses JK-BMS CAN project, and in his case, the EOC flag is triggered when balancing drops below the configured threshold. However, in my case, EOC occurred regardless of balancing. I have the impression that the logic of YamBMS is different, but I don’t understand why there are settings like “Rebulk V” and “Rebulk %.” Which of these settings is active? I’m also unsure about how “Force bulk (top bal)” works. Additionally, I don’t understand the functions of “Request Force Charge Start SoC” and “Request Force Charge Stop SoC.”
In general, I’d like to read more about these options because I can see that the system is very thoughtfully designed, but I don’t yet fully understand it. I also don’t want to ask questions here until I’ve made an effort to understand it on my own. Could I kindly ask for a detailed description of all options with explanations? I’ve searched for it but haven’t been able to find anything.
My friend uses JK-BMS CAN project, and in his case, the EOC flag is triggered when balancing drops below the configured threshold. However, in my case, EOC occurred regardless of balancing. I have the impression that the logic of YamBMS is different, but I don’t understand why there are settings like “Rebulk V” and “Rebulk %.” Which of these settings is active? I’m also unsure about how “Force bulk (top bal)” works. Additionally, I don’t understand the functions of “Request Force Charge Start SoC” and “Request Force Charge Stop SoC.”
In general, I’d like to read more about these options because I can see that the system is very thoughtfully designed, but I don’t yet fully understand it. I also don’t want to ask questions here until I’ve made an effort to understand it on my own. Could I kindly ask for a detailed description of all options with explanations? I’ve searched for it but haven’t been able to find anything.
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First I advise to install the dedicated dashboard in order to have access to all the parameters sorted by categories.
Then, all these functions are already explained in the documentation.
In ancient times, it was in Poland that LiFePo was enriched, and instead of 2700 cycles, it became 10,000. Generous land
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