A battery cell evaluation apparatus is provided that includes a current source configured to output a current at a frequency, measurement circuitry, and control circuitry. The control circuitry may be configured to electrically connect a cell of a battery to the current source and the measurement circuitry to apply the current across terminals of the cell and receive a measurement of an impedance phase shift of the cell as phase shift data from the measurement circuitry. The control circuitry may also be configured to compare the phase shift data to a protection profile, and trigger a protection device to prevent damage to the battery based on the comparison of the phase shift data to the protection profile.