Abstract: A method for evaluating the compression of the cylinders of an internal combustion engine of a vehicle having an electric starter motor and a respective starting battery, comprising: start capturing the battery voltage signal when the starter motor stars to rotate the internal-combustion engine so as to initiate operation of the engine under its own power; cease capturing the battery voltage signal when the engine enters operation under its own power; process the captured voltage signal for the location of local minimums; calculate the time difference between consecutive local minimums; detect if there is a variation of time between the calculated differences higher than a predetermined threshold between any said calculated time differences; and, if there is such variation, signal a potential engine malfunction. Also provided is a device for accomplishing the foregoing.

Abstract: A method for measuring the internal resistance of a multicell automotive battery comprising a plurality of battery cells in series, comprising: scanning the plurality of battery cells to measure their respective voltages until the battery current is stable for a full cell scan with a current value; recording said current value and scanned battery cell voltages; using the recorded current value and battery cell voltages to calculate the internal resistance of each battery cell. Optionally, scanning the plurality of battery cells for measuring their respective voltage until the battery current has been stable for a full cell scan with a second current value which is different from said first current value; recording said second current value and second scanned battery cell voltages; using the recorded first current value, first battery cell voltages, second current value, and second battery cell voltages to calculate the internal resistance of each battery cell.

Abstract: A method for evaluating the compression of the cylinders of an internal combustion engine of a vehicle having an electric starter motor and a respective starting battery, comprising: start capturing the battery voltage signal when the starter motor stars to rotate the internal-combustion engine so as to initiate operation of the engine under its own power; cease capturing the battery voltage signal when the engine enters operation under its own power; process the captured voltage signal for the location of local minimums; calculate the time difference between consecutive local minimums; detect if there is a variation of time between the calculated differences higher than a predetermined threshold between any said calculated time differences; and, if there is such variation, signal a potential engine malfunction. Also provided is a device for accomplishing the foregoing.