Patent ID: 7696724

Claim:
A method of measuring the voltage level of a mobile telephone battery during a charging operation comprising the steps of: (a) applying current from a current source to charge the battery; (b) temporarily causing the current from the current source to cease, to enable the battery to enter a discharge mode; (c) measuring a voltage level of the battery when in the discharge mode; (d) re-applying current from the current source; and (e) repeating steps (b) to (d) until the measured voltage level exceeds one or more pre-determined voltage thresholds, wherein a battery level display on the telephone indicates the charge level of the battery in dependence on which the pre-determined voltage threshold or thresholds has or have been exceeded, and wherein the battery level display indicates a plurality of increasing battery charge levels, wherein each battery charge level corresponds to one of the one or more pre-determined voltage thresholds, wherein steps (a)-(e) are used to determine crossover of each pre-determined voltage threshold of each battery charge level except for a final highest battery charge level, and wherein the method further comprises using a current measurement to determine an end of the battery charging corresponding to the final highest battery charge level.