Method, Arrangement and Computer Program Product for Determining an End-of-Life State of a Battery

A method for determining an end-of-life (EOL) state of a battery, the battery having an initial capacity, the method comprising:

• during a discharge of the battery, measuring a first discharge voltage value provided by the battery at a first point of time;
• during the discharge, measuring a second discharge voltage value) provided by the battery at a second point of time T2;
• computing a predicted backup time based on the first and second discharge voltage values and the first and second points of time;
• during the discharge, measuring a plurality of discharge current values at a plurality of points of time on or between the first point of time and the second point of time;
• computing an average discharge current from the plurality of discharge current values;
• computing an expected backup time based on the initial capacity of the battery and the average discharge current;
• comparing the predicted backup time and the expected backup time;
• and,
• if the expected backup timeup is less than or equal to the predicted backup time, determining the EOL state of the battery.

An arrangement for determining an end-of-life (EOL) state of a battery, the battery having an initial capacity, the arrangement comprising:

• a measuring circuit configured to measure a first discharge voltage value provided by the battery at a first point of time and a second discharge voltage value provided by the battery at a second point of time;
• and
• a processing circuit configured to compute a predicted backup time based on the first and second discharge voltage values and the first and second points in time;
• wherein the measuring part is further configured to measure a plurality of discharge current values at a plurality of points of time on or between the first point of time and the second point of time;
• and
• wherein the processing circuit is further configured to:
• compute an average discharge current from the plurality of discharge current values;
• compute an expected backup time based on the initial capacity of the battery and the average discharge current;
• compare the predicted backup time and the expected backup time;
• and,
• if the expected backup time is less than or equal to the predicted backup time, determine the EOL state of the battery.

A non-transitory computer readable medium storing a computer program for determining an end-of-life (EOL) state of a battery, the battery having an initial capacity, the computer program comprising computer program segments that, when executed by a computer, cause the computer to:

• compute a predicted backup time based on measured values of a first discharge voltage provided by the battery at a first point of time and a second discharge voltage provided by the battery at a second point of time;
• compute an average discharge current from a plurality of measured discharge current values;
• compute an expected backup time based on the initial capacity of the battery and the average discharge current;
• comparing the expected backup time and the predicted backup time;
• and,
• if the expected backup time is less than or equal to the predicted backup time, determine the EOL state of the battery.