Method and apparatus for charging batteries
First Claim
1. A battery charger for charging a battery comprising:
- a sensing circuit which senses at least two different 1st order sense parameters and at least one 2nd order sense parameter;
a charging circuit capable of charging the battery according to a plurality of charging parameters; and
a control circuit which modifies at least two of the charging parameters as a function of the at least two 1st order and at least one 2nd order sense parameters sensed by the sensing circuit.
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Accused Products
Abstract
Batteries are charged using sequences of charge and discharge pulses in which a controller adjusts charge rate and/or terminates the charge process based on measurements taken during the preceding charge cycle and an internally computed algorithmic logic equation to optimize the charge cycle for the battery being charged. A preferred embodiment utilizes six sense parameters, three of which are 1st order (Vps, Vload and Vunload)and three of which are 2nd order (V'"'"'ps, V'"'"'load and V'"'"'unload). The charging scheme is applicable to batteries of many different types, including lead-acid, nickel-cadmium, and nickel-metal-hydride), and requires neither input of battery type nor instrumentation of the battery.
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Citations
22 Claims
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1. A battery charger for charging a battery comprising:
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a sensing circuit which senses at least two different 1st order sense parameters and at least one 2nd order sense parameter; a charging circuit capable of charging the battery according to a plurality of charging parameters; and a control circuit which modifies at least two of the charging parameters as a function of the at least two 1st order and at least one 2nd order sense parameters sensed by the sensing circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of recharging a battery comprising:
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detecting values for at least two parameters selected from the list of power supply voltage, loaded battery voltage, unloaded battery voltage; determining a time derivative of at least one of the detected parameters; using the detected values and the time derivative to determine appropriate charging characteristics; and delivering charging and discharging pulses to the battery in accordance with the appropriate charging characteristics. - View Dependent Claims (13, 14, 15, 16)
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17. A battery charger which automatically accommodates batteries of different chemistries by determining an appropriate cut-off condition for the battery being charged, said battery charger comprising:
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a sense circuit which senses values for at least two different voltages; a first circuit which calculates a time derivative for at least one of the sensed voltages; a second circuit which utilizes the sensed voltages and the time derivative to determine the cut-off condition; a controller which controls delivery of charge and discharge pulses to the battery being charged as a function of the sensed voltages, the time derivative and the cut-off condition. - View Dependent Claims (18, 19, 20)
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- 21. A battery charger capable of safely charging rechargeable batteries using an average charging current in amps of at least five times nominal battery capacity expressed in amp-hours, comprising a sensing circuit, a charging circuit and a control circuit.
Specification