Patent ID: 8760305

Claim:
A method of determining a remaining capacity of an energy source of an information tag, comprising: adjusting a counter at an occurrence of an event which leads to a consumption of energy from the energy source, and determining a remaining capacity of the energy source from a value of the counter; wherein the counter comprises: a first counter for counting the elapsing of a time from a putting into operation of the energy source and determining a value, and a second counter for counting the transmission of information by the information tag and determining a second value, and wherein the remaining capacity of the energy source is determined from the values of the first and second counters; and wherein the determining of the remaining capacity comprises: determining a total rest energy consumption from the value of the first counter and a rest energy consumption value over a period of time between successive adjustments of the first counter; determining a total transmission energy consumption from the value of the second counter and an energy consumption value per transmission by the information tag, determining a total energy consumption from the total rest energy consumption and the total transmission energy consumption, and determining the remaining capacity of the energy source from the total energy consumption and a total capacity of the energy source.