I have been having a back and forth with this vendor about two of the 16 cells they sold me that are weaker than the others. When charging they reach 100% faster, and also reach 0% faster when discharging. All 16 were top balanced to 3.65v. According to the BMS, I only pulled 272 out of 280ah because the two cells reached the disconnect point. They told me to use an active balancer. I said I shouldn’t have to if these are new matched grade A cells.
First they tried to say that it was the BMS’s and my fault because I charged above 3.35v and the disconnect voltage was set at 2.2v(default setting) instead of 2.5v. I said that doesn’t make any sense as to why charging to charging to 100% and discharging deeper means less capacity. Then they went on about loose connections and such.
So they are really digging their heels into there is nothing wrong with the cells they sold. I guessed it was a capacity issue so now they are wanting me to test just these two cells individually. Is that entirely necessary? If they were properly balanced and connected, why would additional testing be needed?
First they tried to say that it was the BMS’s and my fault because I charged above 3.35v and the disconnect voltage was set at 2.2v(default setting) instead of 2.5v. I said that doesn’t make any sense as to why charging to charging to 100% and discharging deeper means less capacity. Then they went on about loose connections and such.
So they are really digging their heels into there is nothing wrong with the cells they sold. I guessed it was a capacity issue so now they are wanting me to test just these two cells individually. Is that entirely necessary? If they were properly balanced and connected, why would additional testing be needed?