8s JK BMS

[Lazeringkids]

Im building a 24v battery with 8 lifep04 Cells with an 8s JK bms. I connected all the individual balance leads to the correct cells. Tested them with meter and I have the right voltage from each cell. I have the main negative going to B- on BMS. Then P- from the BMS going to my negative bus bar.

From my battery main positive to the P- on BMS I'm only getting 22 volts. But my battery is at 26 volts. If I turn on my MPP solar charger/inverter the voltage from from P- on the BMS to the main positive on my battery jumps up to 28 volts.

Lastly the BMS has not turned on at all. No lights, no sounds. Jk BMS app doesn't find it. Nothing.. I've tried setting a charger to 5 volts and connecting the positive from the charger to B- and negative to P- still nothing. Bms just stays the same.

Has anyone dealt with this problem and found a solution? Any help is appreciated. Thanks in advance.

 

[Dynoman]

Im building a 24v battery with 8 lifep04 Cells with an 8s JK bms. I connected all the individual balance leads to the correct cells. Tested them with meter and I have the right voltage from each cell. I have the main negative going to B- on BMS. Then P- from the BMS going to my negative bus bar.

From my battery main positive to the P- on BMS I'm only getting 22 volts. But my battery is at 26 volts. If I turn on my MPP solar charger/inverter the voltage from from P- on the BMS to the main positive on my battery jumps up to 28 volts.

Lastly the BMS has not turned on at all. No lights, no sounds. Jk BMS app doesn't find it. Nothing.. I've tried setting a charger to 5 volts and connecting the positive from the charger to B- and negative to P- still nothing. Bms just stays the same.

Has anyone dealt with this problem and found a solution? Any help is appreciated. Thanks in advance.

Don't have a JK BMS, but there is a way to turn them on. Maybe this will help.

Post in thread 'JK-B2A8S20 BMS Variants'

Jul 8, 2024

I recently installed a JK BMS on a 8S 24 volt build. I felt I was the first person to ever build one. It took me hours to configure. To turn it on you not only have to attach it, but put a powersupply over the leads for a few seconds until it starts to beep and then wait until it stops beeping. What a perfect thing you'd think would be in the documentation.

First off, it has only one RS-485 port that can be used with EITHER an external Bluetooth module OR an external UART-to-USB adapter box.

Mine had a built in Blue Tooth that did not take a UART adapter like My OverKill/JBD...

• chrisski

 

[k490]

Not sure what model you have mine came with a button that connects to the LCD plug. I saw some selling the RS485 USB adaptor, and the power button on eBay. The odd thing was the manual stated to power it on needed 5 volts higher then the battery. I just used the button push once to power it and hold it 5 seconds to power off.

 

[littleharbor2]

You need a charging source to wake up the BMS. Solar charge controllers need to see a battery to start charging. If you are using a SCC then you can jump the neg post on the battery to the SCC negative to wake it up. Of course you need to do this when the sun is out.

 

[José Alves]

Estou construindo uma bateria de 24v com 8 células lifep04 com um 8s JK bms. Conectei todos os cabos de equilíbrio individuais às células corretas. Testei-os com medidor e tenho a voltagem correta de cada célula. Tenho o negativo principal indo para B- no BMS. Então P- do BMS indo para minha barra de barramento negativa.

Do meu positivo principal da bateria para o P- no BMS, estou recebendo apenas 22 volts. Mas minha bateria está em 26 volts. Se eu ligar meu carregador/inversor solar MPP, a voltagem do P- no BMS para o positivo principal na minha bateria salta para 28 volts.

Por fim, o BMS não ligou de jeito nenhum. Nenhuma luz, nenhum som. O aplicativo Jk BMS não o encontra. Nada... Tentei configurar um carregador para 5 volts e conectar o positivo do carregador a B- e o negativo a P-, mas nada. O BMS continua o mesmo.

Alguém já lidou com esse problema e encontrou uma solução? Qualquer ajuda é bem-vinda. Obrigado antecipadamente.

 

[José Alves]

Você tem botão liga e desliga para ligar a bms? Ou o display lcd? As minhas ligam-se das duas maneiras....
Após ligar , já dá as tensões corretas...