BMS reading faulty

[chrisski]

Input welcome.

Have an overkill 8s 100 amp BMS that reads cell 1 and 2 as extremely low, but tests fine with a multimeter. I’ve replaced the ring terminals that measure them and same readings.

This was just installed in my RV but had been used two months ago to pre charge for a top balance two battery packs with no issues.

Tomorrow’s troubleshooting will be set up a second of the same BMS, brand new, for the second battery. If that works, swapping BMS and cables will be the next step.

Edit: User error. Did not have negative battery cable hooked up.

 

[sunshine_eggo]

Did you replace #3 as well?

 

[chrisski]

I did not. I’ll try that tomorrow. Voltage is off there too .

 

[sunshine_eggo]

Yah. I can see it being a cascade from there. would also check continuity from the terminals back to the connector if able.

 

[chrisski]

Yah. I can see it being a cascade from there. would also check continuity from the terminals back to the connector if able.

If only I could find something small enough to go in the connector

 

[sunshine_eggo]

staple?

 

[chrisski]

User error. The main cable to battery needs to be hooked up. I had only connected the small lead. All is well.