Liquid level sensor for battery monitoring systems

A battery electrolyte level monitoring system for a battery having a plurality of cells containing liquid electrolyte, the system comprising:

• a probe for insertion into one cell of the plurality of cells of the liquid electrolyte battery, the probe including:
• a reference electrode, and
• an electrode array including a plurality of array electrodes arranged in a lengthwise direction of the probe, wherein the reference electrode is capacitively coupled to each array electrode;
• and
• a controller electrically coupled to the electrode array, the controller being adapted to:
• for each array electrode, determine a measured value of a capacitive coupling between the reference electrode and the array electrode,
• store the measured value for each array electrode,
• determine an average value of measured values for each array electrode over time,
• store the average value for each array electrode,
• compare the average value for each array electrode with a predetermined range corresponding to an acceptable range of the level of the liquid electrolyte within the one cell of the liquid electrolyte battery, and
• provide a first output if any one of the average values for the array electrodes is above the predetermined range, a second output if all of the average values for the array electrodes are within the predetermined range, and a third output if any one of the average values for the array electrodes below the predetermined acceptable range, the first, second, and third outputs being different from one another.