Need help with BMS not working

[Rswalm]

I have a 48v 400ah battery bank i purchased in China. The BMS is not working and the system digital information screen back light is not working. I was told by the battery manufacturer to take the battery bank to zero to reset the BMS and purchase a 0v activation charger that works with the electrical utility and not the solar charger to recharge the battery. I cannot find anywhere this type of charger.
I have been reading that it is not good for the batteries to go to zero. I am totally confused on what to do to get my battery working again. any ideas?

 

[Rswalm]

By the way it was in parallel with its twin. battery bank two is working fine but battery bank one would not charge. the voltage on battery bank one when i first noticed it was at 32v, it is now at 12.5v

 

[DThames]

By the way it was in parallel with its twin. battery bank two is working fine but battery bank one would not charge. the voltage on battery bank one when i first noticed it was at 32v, it is now at 12.5v

No, not good if it is lithium to discharge that much. Do you have access to the cells and the wiring that connects the cells together?

 

[Pim57]

The BMS most likely disconnected from the battery. So the voltage you are measuring is of no meaning.

The reason for disconnecting can be undervoltage, overvoltage, overcurent, high- or low temperature.

Do you have an app that can connect to the battery?

 

[Rswalm]

The BMS most likely disconnected from the battery. So the voltage you are measuring is of no meaning.

The reason for disconnecting can be undervoltage, overvoltage, overcurent, high- or low temperature.

Do you have an app that can connect to the battery?

I purchased the Epever. i guess the next step is to hook it up to the charger and my laptop. Not sure if this will help. the only way i have to check the battery is with my volt meter.
I think tomorrow i will open the battery case to see if the BMS is hooked up.

 

[Rswalm]

No, not good if it is lithium to discharge that much. Do you have access to the cells and the wiring that connects the cells together?

I think i will open the metal casing tomorrow to see the batteries and test them. what should i look for?

 

[DThames]

I think i will open the metal casing tomorrow to see the batteries and test them. what should i look for?

If it is LiFePo4 type battery, for 48v you should have 16 cells or 16 cell groups in series. You need to measure the voltage on each cell. Normal voltage would be 3.0v to 3.4v if the battery is in a normal state. If any cells are less than 2.5v, that could be real bad news, may have damaged cells. If you can prove all cells are in a normal range, you know the battery cells should be okay if you can fix whatever else might be wrong.

If the cells are good, worse case, is you could add your own BMS and bypass all other electronics of the existing design. Maybe you can find a bad wire or something that is obvious.

 

[Rswalm]

If it is LiFePo4 type battery, for 48v you should have 16 cells or 16 cell groups in series. You need to measure the voltage on each cell. Normal voltage would be 3.0v to 3.4v if the battery is in a normal state. If any cells are less than 2.5v, that could be real bad news, may have damaged cells. If you can prove all cells are in a normal range, you know the battery cells should be okay if you can fix whatever else might be wrong.

If the cells are good, worse case, is you could add your own BMS and bypass all other electronics of the existing design. Maybe you can find a bad wire or something that is obvious.

Thanks, I will do what you suggest this weekend

 

[houseofancients]

I have a 48v 400ah battery bank i purchased in China. The BMS is not working and the system digital information screen back light is not working. I was told by the battery manufacturer to take the battery bank to zero to reset the BMS and purchase a 0v activation charger that works with the electrical utility and not the solar charger to recharge the battery. I cannot find anywhere this type of charger.
I have been reading that it is not good for the batteries to go to zero. I am totally confused on what to do to get my battery working again. any ideas?

can you take a picture of the bms ?

 

[Rswalm]

can you take a picture of the bms ?

No the panel backlight will not come on. But I turned off the solar charger and got the reading on the battery voltage over a few seconds reading 6.6v, 7.8v, and 8v. The battery will not charge from the solar charger even though the charger input readings are 20kw and 13.1amps.

 

[houseofancients]

No the panel backlight will not come on. But I turned off the solar charger and got the reading on the battery voltage over a few seconds reading 6.6v, 7.8v, and 8v. The battery will not charge from the solar charger even though the charger input readings are 20kw and 13.1amps.

what has this tondo with taking a picture with your phone ?

 

[acdoctor]

No the panel backlight will not come on. But I turned off the solar charger and got the reading on the battery voltage over a few seconds reading 6.6v, 7.8v, and 8v. The battery will not charge from the solar charger even though the charger input readings are 20kw and 13.1amps.

A picture of the circuit board inside the battery not the display.