An apparatus and method for discharging a voltage in a battery pack. A method of removing the data embedded in the material, comprises the steps of:removing the data from the material to produce recovered material;deriving the said corrections and locations from the said store; andusing the corrections to correct the recovered material at the said locations. In one embodiment, the active set members are constructively reduced to a single member that is used as a proxy serving cell. More generally, the user has the ability to store predefined call handling criteria, which may be executed by the broadband residential gateway andor the call manager. The capacitance meter is arranged to obtain measurements using the current sensor and the voltage sensor during a measurement duration. Each of the differential amplifiers amplifies and outputs the inputted primary color signal with a different gain characteristic so that the gain characteristic of the signal obtained by mixing the output signals varies at two inflection points.