Li-ion cells and cold temperatures

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I was curious about the behavior of lithium cells at low temperature. In particular I was expecting capacity loss and voltage sag  compared to the standard test temperatures of 20-25°C.

The tests above were conducted on a single cell, a Samsung ICR18650 26F, discharged at 1C.

The voltage sag and loss in capacity are lower than I expected. I am planning to do some -10°C tests to have even more data to compare.