Patent ID: 8718771

Claim:
An implantable medical device, comprising: a battery; a first capacity measuring device configured to calculate battery capacity consumed during a first time period of capacity consumption for the battery; a second capacity measuring device configured to calculate battery capacity consumed during a third time period of capacity consumption for the battery; and a controller connected to the measuring devices, the controller configured to compute an average of the calculated battery capacity from the first capacity measuring device and the calculated battery capacity from the second capacity measuring device weighted according to capacity consumed to determine battery capacity consumed during a second time period of capacity consumption for the battery, wherein the first time period ends at the beginning of the second time period, and the third time period begins at the end of the second time period, wherein, during the second time period, the controller calculates capacity consumed using the equation: Q i = Q i - 1 - Q BEX 2 75 ⁢ % × Q BEX - Q BEX 2 × Q Voltage + ( 1 - Q i - 1 - Q BEX 2 75 ⁢ % × Q BEX - Q BEX 2 ) × Q Coulometer .