Hi all, first time poster and have tried to research before posting. I have a JK BMS (Model K-B2A24S0P). I have it wired to my 16s 48v battery. Battery is made up of 16 - 3.2v 200ah prismatic cells. I have tested it for the correct voltage on the individual pins and have verified voltage on the battery pack. Once I connect the BMS, I do not get any voltage from the battery pack. No red light on the BMS. I have make a 5v battery from AA batteries with a leads, and a 9v battery with leads to short across the B- and P- cables of the BMS still no light. Is there a secret to these things? Looking for any suggestions that others might have come across. Thanks in advance.
Needing help with JK BMS - not turning onb
- Thread starter dbarnrd67
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Nami
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GitHub - NEEY-electronic/JK at JK-BMS
Contribute to NEEY-electronic/JK development by creating an account on GitHub.
github.com
shanemgrey
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This little detail is also causing me a ton of work/frustration. I don't think posting a link to a list of manuals is a good answer to the specific question. However after reviewing the manuals all I find in them is "There is no switch. It will turn on when it detects a charge current".
Since it's really nice to test out a BMS before hooking it up to a charger, it would be great if the other methods of turning it on were more well documented.
I spent hours trying to find a method I could do without having a 60 volt power supply on hand, and not wanting to take the case apart to hit it with 5 volts. I ended up creating a 58volt battery out of some power tool batteries in series with a 30 volt adjustable power supply. Since my bank is currently reading 53volts, 58 should have been perfect. But all I got was a nice big spark when I touched the black lead. So clearly I did something wrong.
Good thing I bought two of them because I may have just smoked the first one.
This seems to be a very common challenge for many users of this BMS and maybe the mfg will take notice and improve the docs or provide a better way to turn it on for testing.
Since it's really nice to test out a BMS before hooking it up to a charger, it would be great if the other methods of turning it on were more well documented.
I spent hours trying to find a method I could do without having a 60 volt power supply on hand, and not wanting to take the case apart to hit it with 5 volts. I ended up creating a 58volt battery out of some power tool batteries in series with a 30 volt adjustable power supply. Since my bank is currently reading 53volts, 58 should have been perfect. But all I got was a nice big spark when I touched the black lead. So clearly I did something wrong.
Good thing I bought two of them because I may have just smoked the first one.
This seems to be a very common challenge for many users of this BMS and maybe the mfg will take notice and improve the docs or provide a better way to turn it on for testing.
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
I use a 9V without issues.
Connect the positive side of the 9 volt to the negative end of the cells, the B- lead of the BMS. Then connect the negative side of the 9 volt battery to the P- lead of the BMS.
It only requires a quick touch to initiate.
Connect the positive side of the 9 volt to the negative end of the cells, the B- lead of the BMS. Then connect the negative side of the 9 volt battery to the P- lead of the BMS.
It only requires a quick touch to initiate.
shanemgrey
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Would a bench power supply do the same? Set to 5 volts or 9?
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
yes it would BUT the "touch" is momentary.
Not sure why charging the battery to turn on BMS is an issue? Once the BMS is on then stop charging and do whatever it is you want to do with the BMS. Doesn't need to be a high charge snd not really different than other methods of turning on.
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
It is NOT charging the Battery to Initialize the BMS. It is about HOW TO INITIALIZE the BMS !
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
Manuals for JK are being updated and clarity are being added for the "shady" areas. From my understanding with discussions with Nami the updated version should be available soon (week or two I believe).
shanemgrey
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"Not sure why charging the battery to turn on BMS is an issue? "
For me it has been an issue because the only power supply I have that goes over 30 volts is my inverter/charger. I know most enthusiasts will have tons of equipment around and a 60 volt PS is probably one of those things. And if you have complete confidence that you have built the battery and connected the BMS correctly, it can make sense to just hook up the whole system and "let er rip!"
I don't have that level of confidence yet and want to get my battery pack tested and working before I risk yet another piece of expensive equipment by some stupid mistake. So for me, it would be very handy to have an easy way (like a switch) to initialize the bms.
The manual does indeed say charging is required and there is no other option. I'm not saying it's wrong, or that the info isn't there. I'm saying it would be very nice for there to be another option, and that other option be documented.
For me it has been an issue because the only power supply I have that goes over 30 volts is my inverter/charger. I know most enthusiasts will have tons of equipment around and a 60 volt PS is probably one of those things. And if you have complete confidence that you have built the battery and connected the BMS correctly, it can make sense to just hook up the whole system and "let er rip!"
I don't have that level of confidence yet and want to get my battery pack tested and working before I risk yet another piece of expensive equipment by some stupid mistake. So for me, it would be very handy to have an easy way (like a switch) to initialize the bms.
The manual does indeed say charging is required and there is no other option. I'm not saying it's wrong, or that the info isn't there. I'm saying it would be very nice for there to be another option, and that other option be documented.
Ampster
Renewable Energy Hobbyist
The way I see it is if the BMS has shut down because of low voltage, having a switch would just turn it on to further drain the battery. Charging is the only safe way to avoid draining the battery.
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
To Initialize a JKBMS, a 9V battery is CHEAP. A connector for one is Pennies, you can even use Crocodile Aligator Clips if your careful. No serious expense, easy and works. The how to provided above works and @Nami & @upnorthandpersonal will confirm such.
Having Charger ON and pushing power to ReEnable a Shutdown BMS is another separate issue and the APP does have an Emergency ON setting provided the cells are not flat.
Every BMS Brand & Model is DIFFERENT, as is their setup, firmware/software etc. Keep that in mind too.
Having Charger ON and pushing power to ReEnable a Shutdown BMS is another separate issue and the APP does have an Emergency ON setting provided the cells are not flat.
Every BMS Brand & Model is DIFFERENT, as is their setup, firmware/software etc. Keep that in mind too.
shanemgrey
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I appreciate you sharing that method here. I'll try it today if I can find a 9 volt around. Getting one could mean a two hour round trip to the closest store that sells them though. So I'll probably use my power supply or a stack of NHMH cells if I don't have a 9 volt.
It's great that the manuals are getting updates. This seems to be a really great BMS for the price and I think it will only get more popular as the documentation becomes more clear.
It's great that the manuals are getting updates. This seems to be a really great BMS for the price and I think it will only get more popular as the documentation becomes more clear.
shanemgrey
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After carefully checking everything over 5 more times ;-) I tried this, and it worked. Had to hold the connection for maybe 2 seconds before it turned on. No magic smoke this time. Thank you!
Then I ran into the next issue. The android could see the BT device in the list of devices in the area, but the app didn't bring it up when scanning.
The solution in my case was to turn on location access for the app. I think it probably asked for that initially, but I denied it as I usually do. Why would a BMS app need to know the GPS coordinates? It's bad enough that the APK is unsigned and skirts any security provided by the play store. This app makes the phone insecure. So I put it on an old phone after a factory reset.
The next step is to complete the battery pack build so that I have leads coming out of it and everything is sealed up to keep the mice and snakes out of the box.
42OhmsPA
What's in a title?
Thanks for the info on turing them on, I'm ordering 2 whenever Jenny sends the quote back.
The location access isn't an app thing, it's an android /Google thing...
Steve_S
Offgrid Cabineer, N.E. Ontario, Canada
Yes, the GPS access the Android needing.
You have to have Version 6 or better on Android to run the current App btw.
I have 4 JKBMS' running now, 2 more to go to complete everything. Had to wait on Minutia Parts to finally arrive...
You have to have Version 6 or better on Android to run the current App btw.
I have 4 JKBMS' running now, 2 more to go to complete everything. Had to wait on Minutia Parts to finally arrive...
It's not a "let er rip!" scenario. The BMS does not function on its own. Its power comes from the battery and needs to be properly connected and then activated. That's why you need to double, triple check connections. If you have solar then you can use this to activate. Doesn't need much current and will turn on quickly. You can then disconnect if you then want to play around. Either way you activate it, if the wiring is wrong, the BMS may fail.
OffGridIdaho
Hobby Farm in N Idaho
1 picture worth 1,000 words.
