Battery Charging Issue

[smorgan345]

Hi ,
I got an SOK 100 Ah battery 12V lithium battery. When I put a multi-meter on it reads like .4 volts. When I hook my charger up to it the charging shows it as fully charged and doesn't charge it. If I put the meter on it with the charger hooked to it I get a 12.9v reading. Then I disconnect the charger and it reads .4 volts again. So I took the battery apart and removed the BMS to test the cells. They are registering around .4 volts. But when I hook the charger to just one cell it starts to charge it. I'm wondering if it's safe to charge the cells separately and then put it all back together and hopefully it will reset whatever problem is happening. Clearly I don't know what I'm doing so I thought I would check here to see if anyone had any input. Thanks in advance.

 

[42OhmsPA]

Stop what you are doing and contacted your retailer for support.
Unless you are are using a power supply set to 3.65v or less and verified with a DMM with nothing else connected you don't want to charge individual cells without the BMS.
Sounds like you need to wake up the BMS and/or enable charging. Are you able to communicate with it over Bluetooth?

 

[Bob B]

Is this a brand new battery or one you've had for a while?

 

[Bud Martin]

Hi ,
I got an SOK 100 Ah battery 12V lithium battery. When I put a multi-meter on it reads like .4 volts. When I hook my charger up to it the charging shows it as fully charged and doesn't charge it. If I put the meter on it with the charger hooked to it I get a 12.9v reading. Then I disconnect the charger and it reads .4 volts again. So I took the battery apart and removed the BMS to test the cells. They are registering around .4 volts. But when I hook the charger to just one cell it starts to charge it. I'm wondering if it's safe to charge the cells separately and then put it all back together and hopefully it will reset whatever problem is happening. Clearly I don't know what I'm doing so I thought I would check here to see if anyone had any input. Thanks in advance.

Are you saying each cell shows 0.4V?
So you hook up 12V charger to one cell and it starts charging? I am surprised that the charger did not into shutdown due to low Voltage is detected or blow up something.
What kind of charger is it? Makes and model?

 

[smorgan345]

Are you saying each cell shows 0.4V?
So you hook up 12V charger to one cell and it starts charging? I am surprised that the charger did not into shutdown due to low Voltage is detected or blow up something.
What kind of charger is it? Makes and model?

It is an EG4 Signature Solar 12V LifePO4 Charger, Max Output Current 15.0 ADC. It has a green light on it when the battery is charged and the light is red when it's charging. When I hook it to the assembled battery the green light is on. But if I hook it to a standalone cell it is red. Sounds like I shouldn't have done that though. I only did it for a second and then thought I should ask. Yes each cell shows 0.4V

 

[smorgan345]

Is this a brand new battery or one you've had for a while?

It's basically new. I've had it for a while but I've never been able to get it to work right. I have a 1000W Renogy inverter I was trying to use with it but every time I turned it on it would trip the BMS and the battery would shut down. I'd have to charge it to get it to come back. So the SOK people sent me a new BMS that I installed. It worked once with the inverter but then it stopped and now I can't get it to charge. For some reason the charger thinks its already charged. I tried charging it with the solar panel through the charge controller and it reads that it's fully charged but then when I disconnect the panel it goes down to the .4v I was talking about. I thought it might be the new BMS so I put the old one back in but same problem.

 

[smorgan345]

Stop what you are doing and contacted your retailer for support.
Unless you are are using a power supply set to 3.65v or less and verified with a DMM with nothing else connected you don't want to charge individual cells without the BMS.
Sounds like you need to wake up the BMS and/or enable charging. Are you able to communicate with it over Bluetooth?

Ok, good thing I checked, thank you. No I don't have a bluetooth connection to it

 

[Bud Martin]

It is hard to believe that all the cells in the SOK show 0.4V.
Can you show us the inside of that SOK and where the readings were taken?

 

[Bob B]

I would also be a little concerned that by hooking up the higher voltage to individual cells with the BMS attached that the BMS could be damaged.
If the battery has never worked correctly, I would be trying to get the vendor to replace it.

 

[smorgan345]

It is hard to believe that all the cells in the SOK show 0.4V.
Can you show us the inside of that SOK and where the readings were taken?

 

[smorgan345]

I would also be a little concerned that by hooking up the higher voltage to individual cells with the BMS attached that the BMS could be damaged.
If the battery has never worked correctly, I would be trying to get the vendor to replace it.

I didn't hook the higher voltage to the cells while the BMS was attached. I removed the BMS first so hopefully its all good. I have 2 BMSs from the vendor and both do the same thing so I don't know. I attached some photos to another reply on the thread that might help show what I mean. Thanks for looking.

 

[42OhmsPA]

I would definitely contact the vendor you purchased the battery from and/or order a bench power supply to attempt to recharge cells individually followed by a top balance.
Ps, that rigid shop vac is awesome, so quiet and sucks great! I've used and abused mine for years.

 

[Bud Martin]

Contact SOK and show them the pictures and the link to this forum.