The value of the internal resistance
Question: In your promotional materials you mention several times that the internal resistance of the LTO cells is “very low”, “lower than for the LFP cells”, is “only 1 mOhm and less”. However we have tested the internal resistance and the value is more than 20 mOhm. We think your information is not correct.
First, note that the internal resistance of the cell is not a constant value. The internal resistance increases when the cell is fully charged and also increases when the cell is getting discharged. To measure the internal resistance for reference value, you should measure within DOD of 80% to 20%. This means after you charge the cell to full, you let the cell discharge to 80% first and only after that you perform the tests.