Impedance differences

[Robbert Verboon]

I have a new battery bank with 3 x 16 Eve Cells. I notice a big difference in the Impedance between the cells. Varying from 0.369 mOhm to 14.342 mOhm.

Cells are not yet balanced. What can be the reason for the difference in impedance?
Any solution?

 

[Skypower]

I have a new battery bank with 3 x 16 Eve Cells. I notice a big difference in the Impedance between the cells. Varying from 0.369 mOhm to 14.342 mOhm.

Cells are not yet balanced. What can be the reason for the difference in impedance?
Any solution?

Crud under the buss bars

 

[SeaGal]

Varying from 0.369 mOhm to 14.342 mOhm.

14mOhm is not good - that would result in a voltage drop of 1.4V at 100A

 

[ricardocello]

at 100A, Power dissipation is = I^2 R = (100)(100)(0.0143) = 143W of heat !!

 

[SeaGal]

... well that saves having to heat your cells over Winter

 

[wpns]

I have a new battery bank with 3 x 16 Eve Cells. I notice a big difference in the Impedance between the cells. Varying from 0.369 mOhm to 14.342 mOhm.

Cells are not yet balanced. What can be the reason for the difference in impedance?
Any solution?

Well, you want to get the cells balanced before comparing too carefully, but those three {3,8,14} have some serious issues, I'd check the connections, disassemble, clean, and reassemble with the correct torque, etc.

 

[Robbert Verboon]

Thanks everyone. No heat developing but charge is low as batterybis full. Will clean the connections.

 

[frankrudis65]

Check every single cell without busbars....Bad connections are the most common address to search for.I found a bad ac connection the other day,which carbonized some centimeters of cable....With those heavy busbars,I can imagine the sparks