DC IR vs SOC (IV)

Further to the data on internal resistance I have been collecting while modelling cells.

I have measured slight increases in DC IR when cells have reached 90% of their original capacity, I can give that data if interested. It is useful to see how a cell reacts when it has been cycled and has aged a bit, an essential aspect for power applications.

To get the IR data at 90% ( and later 80%) I have been cycling cells in my bunker on a Cadex C7400.

NCR18650BF. Charge at 0.5C. Discharge at 0.5C

NCR18650GA. Charge at 0.5C. Discharge at 1C

INR18560-35E. Charge at 0.5C. Discharge at 1C

 The NCR18650GA has almost reached 80% at 343 cycles.

The INR18650-35E from Samsung seems to be doing better.

 This is a test of just one cell, cell to cell variability is unknown.