Abstract: A battery detect circuit (32) is connected to a battery, with the current A battery V:the battery and the current extracted from the battery measured with a sense resistor (50) and convened to charge and discharge voltages with a V/F converter (52). A microcontroller (64) is operable to increment a nominal available charge (NAC) register (180) during a charge operation and to increment a discharge rate counter (DCR) (184) during a discharge operation. The NAC register (180) indicates the available charge, i.e. the charge state of the battery, which value is output to a display (34). The display (34) is controlled to operate in either an absolute full mode or a relative full mode. This is determined by an external programming pin which has first and second programming states associated with the two modes.

Abstract: A battery detect circuit (32) is connected to the battery with the current input to the battery and extracted from the battery measured with a sense resistor (50) and then converted to charge and discharge pulses with a V/F converter (52). A microcontroller (64) is operable to increment a Nominal Available Charge (NAC) register (180) during a charge operation, and to increment a Discharge Count Register (DCR) (184) during a discharge operation. The NAC register (180) indicates the available charge, which value is output to a display (34). The maximum value to which the NAC value can rise is limited by a value stored in the last measured discharge register (182). This value represents the value stored in the DCR (184) whenever the battery is discharged from an apparent full state to a fully discharged state. This results in a qualified transfer to the LMD register (182) such that no knowledge of the actual battery charge is necessary.

Abstract: A battery detect circuit (32) is connected to the battery with the current input to the battery and extracted from the battery measured with a sense resistor (50) and then converted to charge and discharge pulses with a V/F converter (52). A microcontroller (64) is operable to increment a Nominal Available Charge (NAC) register (180) during a charge operation, and to increment a Discharge Count Register (DCR) (184) during a discharge operation. The NAC register (180) indicates the available charge, which value is output to a display (34). The maximum value to which the NAC value can rise is limited by a value stored in the last measured discharge register (182). This value represents the value stored in the DCR (184) whenever the battery is discharged from an apparent full state to a fully discharged state. This results in a qualified transfer to the LMD register (182) such that no knowledge of the actual battery charge is necessary.

Abstract: A battery detect circuit (32) is connected to the battery with the current input to the battery and extracted from the battery measured with a sense resistor (50) and then converted to charge and discharge pulses with a V/F converter (52). A microcontroller (64) is operable to increment a Nominal Available Charge (NAC) register (180) during a charge operation, and to increment a Discharge Count Register (DCR) (184) during a discharge operation. The NAC register (180) indicates the available charge, which value is output to a display (34). The maximum value to which the NAC value can rise is limited by a value stored in the last measured discharge register (182). This value represents the value stored in the DCR (184) whenever the battery is discharged from an apparent full state to a fully discharged state. This results in a qualified transfer to the LMD register (182) such that no knowledge of the actual battery charge is necessary.