Method and circuitry to determine temperature and/or state of health of a battery/cell

A method to determine a temperature of a battery, wherein the battery includes at least two terminals, the method comprising:

• applying a first calibration packet to the terminals of the battery at a first state of charge (SOC) of the battery, wherein the first calibration packet includes a first pulse and a rest period, wherein the first pulse temporally precedes the rest period;
• measuring a plurality of voltages at the terminals of the battery, including:
• a first terminal voltage at a time immediately prior to or at a beginning of the application of the first pulse of the first calibration packet, and
• a second terminal voltage, in response to the first calibration packet, at a time during the partial relaxation time period of a battery;
• determining a partial relaxation time voltage (VPRT) at the first SOC of the battery using the first and second terminal voltages;
• and
• determining a temperature of the battery by correlating the partial relaxation time voltage (VPRT) at the first SOC of the battery to a temperature of the battery for the first SOC and a particular state of health (SOH) of the battery.