METHOD AND APPARATUS FOR DETERMINING DEPLETED CAPACITY OF A BATTERY

摘要

In a method for determining depleted capacity of a battery (2) of CFx type used in an implantable medical device average values of battery voltage and current drawn for the battery (2) are measured during a measurement time. The lenght of this measurement time exceeds a battery voltage recovery time after a load change. Predetermined relations between, on one hand, combinations of average values of voltage and current and, on the other hand, depleted battery capacity are used for determining depleted capacity of the battery for the measured average voltage and current. An apparatus for determining depleted capacity of a battery of this type used in an implantable device comprises averaging means provided to determine average values of battery voltage and current drawn from the battery (2) during a measurement time. The lenght of the measurement time exceeds a battery voltage recovery time after a load change. A determining means is provided for determining actual depleted battery capacity from predetermined relations between, on one hand, combinations of average values of voltage and current and, on the other, depleted battery capacity. A pacemaker comprises such an appartus.