Method and apparatus for charging a lead-acid battery
First Claim
1. A method of charging a lead-acid battery which comprises providing a variable power supply to charge the battery with an applied voltage, periodically carrying out a voltage sweep through a predetermined range, detecting the applied voltage and current at multiple points as the voltage sweep is being carried out, detecting a slope based upon the applied voltage and current values detected during the voltage sweep that is substantially a maximum slope value, selecting a charging voltage for the battery being charged from the detected values for applied voltage and current wherein the selected voltage corresponds to a voltage greater than the voltage at the maximum slope value, and adjusting the variable power supply to provide the battery being charged with a charging voltage based upon the charging voltage value selected.
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Accused Products
Abstract
A method and apparatus is disclosed for charging lead-acid batteries which includes periodic voltage sweeps to determine the charging voltage that should be used for the battery and then adjusting the charging voltage in accordance with that voltage sweep information so as to ensure that a highly efficient charging process is achieved which avoids undue gassing and inherently compensates for factors such as the temperature, type and service life history of the battery and resistance due to the interactive nature of the technique and apparatus.
256 Citations
34 Claims
- 1. A method of charging a lead-acid battery which comprises providing a variable power supply to charge the battery with an applied voltage, periodically carrying out a voltage sweep through a predetermined range, detecting the applied voltage and current at multiple points as the voltage sweep is being carried out, detecting a slope based upon the applied voltage and current values detected during the voltage sweep that is substantially a maximum slope value, selecting a charging voltage for the battery being charged from the detected values for applied voltage and current wherein the selected voltage corresponds to a voltage greater than the voltage at the maximum slope value, and adjusting the variable power supply to provide the battery being charged with a charging voltage based upon the charging voltage value selected.
- 8. An apparatus for charging a lead-acid battery which comprises a variable DC power supply for charging the battery, a DC voltage output controller to control the voltage of the DC power supply, a voltage sweep function generator for applying a voltage sweep through a predetermined range to the battery being charged, detection means to determine the voltage and current at multiple points and times as the voltage sweep is carried out and providing voltage and current signals based upon such detected values, said detection means including means for detecting a maximum slope value based upon the applied voltage and current values detected during the voltage sweep, an analyzer means for receiving the voltage and current signals at the various times detected and selecting a charging voltage greater than the voltage at the maximum slope value, said DC voltage output controller receiving the charging voltage information and adjusting the voltage of said variable DC power supply so that the battery being charged is provided with the selected charging voltage.
- 11. A method of controlling the charging of a lead-acid battery by adjusting the charging voltage in accordance with periodic voltage sweeps which comprises detecting the voltage of the battery being charged, lowering the voltage being applied to the battery until a minimum acceptable level of current is detected, initiating the voltage sweep over a predetermined range at an augmented voltage rate with time, detecting whether the maximum current for the charger power supply has been reached, setting the charging voltage at that point if the maximum current has been reached and stopping the voltage sweep at or above that point, continuing the voltage sweep when the charger current has not been maximized, determining voltage and current values at intervals during the voltage sweep, detecting whether a maximum slope value has been reached based upon the applied voltage and current values detected during the voltage sweep, selecting the charging voltage based upon the current-voltage values determined wherein the selected charging voltage is greater than the voltage at the maximum slope value, terminating the voltage sweep, delaying for a predetermined period of time and thereafter initiating a further voltage sweep.
- 22. A method of charging a lead-acid battery which comprises providing a variable power supply to charge the battery with an applied voltage, periodically carrying out a voltage sweep through a predetermined range, detecting the applied voltage and current at multiple points as the voltage sweep is being carried out, detecting a selected slope value based upon the applied voltage and current values detected during the voltage sweep, selecting a charging voltage value as the voltage corresponding to the voltage at the selected slope value, and adjusting the variable power supply to provide the battery being charged with a charging voltage based upon the charging voltage value selected.
- 27. A method of charging a lead-acid battery which comprises providing a variable power supply to charge the battery with an applied voltage, periodically carrying out a voltage sweep through a predetermined range, detecting the applied voltage and current at multiple points as the voltage sweep is being carried out, selecting a charging voltage for the battery being charged from the detected values for applied voltage and current, adjusting the variable power supply to provide the battery being charged with a charging voltage based upon the charging voltage value selected, determining whether the battery has reached a desired level of charge from the detected values for applied voltage and current over a plurality of sweeps, and terminating sweep charging when the battery is determined to be substantially charged.
- 30. A method of charging a lead-acid battery which comprises providing a variable power supply to charge the battery with an applied voltage, selectively discharging the battery, periodically carrying out a voltage sweep through a predetermined range, detecting the applied voltage and current at multiple points as the voltage sweep is being carried out, selecting a charging voltage for the battery being charged from the detected values for applied voltage and current, and adjusting the variable power supply to provide the battery being charged with a charging voltage based upon the charging voltage value selected.
- 32. An apparatus for charging a lead-acid battery which comprises a variable DC power supply for charging the battery, a DC voltage output controller to control the voltage of the DC power supply, discharge means for selectively providing a discharge pulse to the battery, a voltage sweep function generator for applying a voltage sweep through a predetermined range to the battery being charged, detection means to determine the voltage and current at multiple points and times as the voltage sweep is carried out and providing voltage and current signals based upon such detected values, an analyzer means receiving the voltage and current signals at the various times detected and selecting a charging voltage, said DC voltage output controller receiving the charging voltage information and adjusting the voltage of said variable DC power supply so that the battery being charged is provided with the selected charging voltage.
Specification