Lithium battery charging observations

[mojoman]

I currently testing my 900AH lithium pack consisting of (20) 180AH CALB cells. I observed cell voltages vary depending where they are in the bank during charging. I'm using a 40 amp charger for my testing. The BMS eventually balances the cells out but it takes time. These cells were bottom balanced initially.
This tells me that my configuration/#number of cells require a settling period to accurately measure SOC and reach desired % of charge. If I depended on the automated cutouts, it would charge to a lower % SOC, after settling.

[mojoman]

Monitoring the cell voltage, 2.5-3.7v and temperature is critical in maximizing the performance and longevity of these cells. Keeping them at room temperature is the best environment for these cells if you want max performance and longevity. 80% SOC is the best setting for longevity of the cells and charging to 100% SOC just prior to heavy use is a better plan. Installing the batteries outside the RV does not make any sense since it lowers their performance and longevity, the two things you paid a premium for using this technology.