Trying to Calibrate JK BMS
- Thread starter BigBrosMo
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FilterGuy
Solar Engineering Consultant - EG4 and Consumers
Did you ever get this resolved?
BigBrosMo
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Yes and no. Not really, but kind of. Does that help?
I figured out that the only values it would accept are within a range of what it measures. eg. If I measure 26.8v with my volt meter, and the BMS is showing 27v, I can calibrate it to something like 26.92 but not to 26.91 or lower. So I can get close to my volt meter but not exactly. It annoys me as that drives the current reading off over time from my battery monitor (which has no calibration settings) and yet is dialed into my Volt meter.
If you figure it out, or acquire any insight let me know!
same here, very annoying, and JK appear to have turned off their "Support" facility, probably because of the massive stuff up with the last firmware update.
same problem here my jk bd6a20610p Voc read 27.02 but my quality MM reads 26.76V 260mV difference - unacceptable IMHO for a Lifepo. Cant get a calibration accepted? Im afraid to go for an update - lot of bad news reported here about JK updates and it loses your setting and password and locks you out. REALLY BAD NEWS FOR JK BMS - I SHALL SHOUT AT ANDY - NOT HIS FAULT OF COURSE BUT HE USED TO HAVE AN INSIDE TRACK but in spite of all his good free work with them their teams seems to have evaporated - so no real personal contact anymore. JK sure know how to trash their brand.
This now means that I cant trust cell volt setting inside the works - we all know how critical these 4 digit data values are. Accuracy is essential. I will have to dig inside now and make direct measurements and compare with what the app says
Will report back - what a PITA
Robin
I check with Andy's site and its worse than I thought
Quote
32,961 views 31 Jul 2024
Here is a small collection of all the problems and issues I have found in my comments, some forums and you sent me via email about the JK-BMS.And, I'm not sure if they will be fixed and if JK is still actively developing their firmware.Some new firmware versions are floating around in the interwebs but they are not officially on the JK-BMS website for download. Lots of communication issues and customer service complaints have been reported, next to all these technical problems with the BMS.It seems, the glory days of actively working with the JK team and develop new firmware quickly and efficiently are over!So, is it time to move on and look for something else?
UQ
Thats a pretty damning comments on JK - are they trying to destroy their brand completely and it gets worse Andy's update site gives the latest firmware stuff https://off-grid-garage.com/battery-management-systems-bms/
but I dug into it and I am on V11.286 and the latest is V 15.27 and the update procedure looks very scary. What about all the previous stuff - have I got work my way up? no instructions. FW updates not shown on their website. I could so easily end up with a brick!!!!!!!!!!!!!!!!!!!!
So I wont do anything - So much for JK customer support
This now means that I cant trust cell volt setting inside the works - we all know how critical these 4 digit data values are. Accuracy is essential. I will have to dig inside now and make direct measurements and compare with what the app says
Will report back - what a PITA
Robin
I check with Andy's site and its worse than I thought
Quote
32,961 views 31 Jul 2024
Here is a small collection of all the problems and issues I have found in my comments, some forums and you sent me via email about the JK-BMS.And, I'm not sure if they will be fixed and if JK is still actively developing their firmware.Some new firmware versions are floating around in the interwebs but they are not officially on the JK-BMS website for download. Lots of communication issues and customer service complaints have been reported, next to all these technical problems with the BMS.It seems, the glory days of actively working with the JK team and develop new firmware quickly and efficiently are over!So, is it time to move on and look for something else?
UQ
Thats a pretty damning comments on JK - are they trying to destroy their brand completely and it gets worse Andy's update site gives the latest firmware stuff https://off-grid-garage.com/battery-management-systems-bms/
but I dug into it and I am on V11.286 and the latest is V 15.27 and the update procedure looks very scary. What about all the previous stuff - have I got work my way up? no instructions. FW updates not shown on their website. I could so easily end up with a brick!!!!!!!!!!!!!!!!!!!!
So I wont do anything - So much for JK customer support
Last edited:
Jk has no customer support, but are the best for DIY and kind of cheap
JK are not loved by the installers, as they usually dont want to learn about batteries or settings, that’s why the “miracle” called Pace BMS is used as plug&pray.
JK are not loved by the installers, as they usually dont want to learn about batteries or settings, that’s why the “miracle” called Pace BMS is used as plug&pray.
Anyone had this issue with a larger voltage delta? Have a 4S-24S 40A-300A BMS that will not accept the correct voltage calibration. Continue to get the "Sending failure" error.
Cell stack voltage sits at 50V and the lowest calibration voltage is 63.88V. Will accept higher calibration values. All other calibration values are accepted. Have also messed with the cell level OVP and UVP values to make sure everything is within range. Tried turning off all controls as well based on other post suggestions with no luck. Even ordered a second BMS (they sent a different HW & SW) but had the same exact issue.
Hardware: V19H
Software Ver: V19.03
Any insight would be greatly appreciated
Cell stack voltage sits at 50V and the lowest calibration voltage is 63.88V. Will accept higher calibration values. All other calibration values are accepted. Have also messed with the cell level OVP and UVP values to make sure everything is within range. Tried turning off all controls as well based on other post suggestions with no luck. Even ordered a second BMS (they sent a different HW & SW) but had the same exact issue.
Hardware: V19H
Software Ver: V19.03
Any insight would be greatly appreciated
The two measurements should not be equal. The BMS measurement (27.0V) is the sum of all the cell voltages. You measure 26.8V at the battery terminals. The measurements are taken at two different locations. They will not be equal. There are two back to back MOSFET switches between those locations. The switches will have a voltage drop.
I really don't know what you're talking about. Provide a link, be exact!
One thing I know for sure, while current is equal throughout a series circuit, voltage is not. There are voltage drops across the entire circuit. The sum of the series cell voltages will always be greater than the voltage at the battery terminals.
Everybody seems to be singing the same song, including the manufacturer!
I think you might be splitting hairs?
I think you might be splitting hairs?
Nothing what you posted is inconsistent with what I've said. No one is singing any song. You're just trying to spin one.
The OP and you as well make a monumental mistake. You've failed to provide detailed info on your battery. When making the voltage calibration, do you have access to the individual cells? The calibration works only if you can measure battery voltage prior to any BMS to cell connection. That means the cells have to be accessible. Since you never stated you can measure cell voltages, I've assumed you can only measure battery voltage after the BMS. Voltage calibration is now worthless.
BTW, the video you posted is a joke. It looks like the guy is using a Klein 325 multimeter. It has an accuracy of 0.8% plus 3 digits. He's reading 54.2 V with a +/- 0.7V possible error. The two measurements (meter and BMS) differed by only 0.4V. 0.4V is within the error range of the meter.
The OP and you as well make a monumental mistake. You've failed to provide detailed info on your battery. When making the voltage calibration, do you have access to the individual cells? The calibration works only if you can measure battery voltage prior to any BMS to cell connection. That means the cells have to be accessible. Since you never stated you can measure cell voltages, I've assumed you can only measure battery voltage after the BMS. Voltage calibration is now worthless.
BTW, the video you posted is a joke. It looks like the guy is using a Klein 325 multimeter. It has an accuracy of 0.8% plus 3 digits. He's reading 54.2 V with a +/- 0.7V possible error. The two measurements (meter and BMS) differed by only 0.4V. 0.4V is within the error range of the meter.
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