Method and apparatus for charging a battery
First Claim
1. A method of charging a battery comprising the steps of (a) testing said battery by supplying energy thereto and measuring the voltage thereacross, and deriving therefrom the dynamic voltage-current characteristic of said battery as a function of the charge condition thereof;
- (b) charging said battery by supplying a gradually varying voltage thereto, substantially without controlling the current supplied to said battery, for a predetermined time, the rate at which said supplied voltage varies being related to said dynamic voltage-current characteristic obtained in step (a); and
(c) repeating steps (a) and (b) alternately until the dynamic voltage-current characteristic last obtained is substantially identical to the preceding dynamic voltage-current characteristic, whereupon the charging of said battery is terminated.
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Accused Products
Abstract
A battery is charged by repeatedly alternating between test and charge cycles. During the test cycle, the dynamic voltage-current characteristic of the battery is obtained as a function of the charge condition of the battery. During the charge cycle, a gradually varying voltage is supplied to the battery, substantially without controlling the current supplied thereto, for a predetermined time. The rate at which this supplied voltage varies is related to the dynamic voltage-current characteristic obtained during the test cycle. Alternating between test and charge cycles continues until the dynamic voltage-current characteristic last obtained is substantially identical to the preceding dynamic voltage-current characteristic, whereupon the charging of the battery is terminated.
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Citations
56 Claims
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1. A method of charging a battery comprising the steps of (a) testing said battery by supplying energy thereto and measuring the voltage thereacross, and deriving therefrom the dynamic voltage-current characteristic of said battery as a function of the charge condition thereof;
- (b) charging said battery by supplying a gradually varying voltage thereto, substantially without controlling the current supplied to said battery, for a predetermined time, the rate at which said supplied voltage varies being related to said dynamic voltage-current characteristic obtained in step (a); and
(c) repeating steps (a) and (b) alternately until the dynamic voltage-current characteristic last obtained is substantially identical to the preceding dynamic voltage-current characteristic, whereupon the charging of said battery is terminated. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
- (b) charging said battery by supplying a gradually varying voltage thereto, substantially without controlling the current supplied to said battery, for a predetermined time, the rate at which said supplied voltage varies being related to said dynamic voltage-current characteristic obtained in step (a); and
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20. A method of charging a battery comprising the steps of carrying out a test cycle by supplying a controllably varying charging current to said battery, measuring the voltage produced across said battery in response to the charging current supplied thereto while said charging current is being supplied, obtaining the dynamic voltage-current characteristic of said battery as a function of the supplied charging current and measured voltage, and determining predetermined characteristics of said battery, including the charge capacity, charge condition and selected faults, in accordance with said dynamic voltage-current characteristic;
- carrying out a charge cycle for a predetermined time by supplying a ramp voltage to said battery having a slope established in accordance with said dynamic voltage-current characteristic; and
alternately carrying out said test and charge cycles until predetermined features of the last-obtained dynamic voltage-current characteristic are substantially identical to said predetermined features of the preceding dynamic voltage-current characteristic. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31)
- carrying out a charge cycle for a predetermined time by supplying a ramp voltage to said battery having a slope established in accordance with said dynamic voltage-current characteristic; and
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32. Apparatus for charging a battery comprising energizing means coupled to said battery to supply energy thereto;
- sensing means coupled to said battery to sense voltage thereacross and current thereto; and
control means coupled to said energizing means and to said sensing means for controlling the energy supplied to said battery by said energizing means during a test cycle and responsive to at least one of the voltage and current sensed during said test cycle to obtain the dynamic voltage-current characteristic of said battery and to determine the charge condition of said battery as a function of said dynamic voltage-current characteristic;
said control means being operative during a charge cycle for controlling said energizing means to supply a gradually varying voltage to said battery, substantially without controlling the current supplied thereto, at a rate related to said dynamic voltage-current characteristic; and
said control means being operative to alternate between said test cycle and said charge cycle until the latest dynamic voltage-current characteristic obtained thereby is substantially identical to the preceding dynamic voltage-current characteristic. - View Dependent Claims (33, 34, 35, 36, 37, 38, 39, 40)
- sensing means coupled to said battery to sense voltage thereacross and current thereto; and
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41. Apparatus for charging a battery comprising energizing means coupled to said battery to selectively supply current and voltage thereto;
- sensing means coupled to said battery to sense voltage thereacross; and
data processing means programmed to alternate repeatedly between a test cycle and a charge cycle and for controlling said energizing means during each cycle, said data processing means being programmed to control said energizing means during a test cycle to supply current to said battery and being programmed to control said sensing means during a test cycle to sense the voltage across said battery, said data processing means being further programmed during a test cycle to derive the dynamic voltage-current characteristic of said battery for determining the charge condition of said battery as a function of the sensed voltage and for terminating further charge cycles when said data processing means determines the battery to be fully charged. - View Dependent Claims (42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55)
- sensing means coupled to said battery to sense voltage thereacross; and
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56. Apparatus for charging a battery comprising energizing means coupled to said battery to selectively supply current and voltage thereto;
- sensing means coupled to said battery to sense voltage thereacross; and
data processing means programmed to repeatedly establish and alternate between a test cycle and a charge cycle and for controlling said energizing means during each cycle, said data processing means including memory means for storing charge capacity data representing charge capacities of different batteries, gas voltage data representing the gas voltage levels of said batteries, charge level data representing the charge levels of said batteries as a function of the battery voltage thereof, charging voltage data representing predetermined parameters relating to charging voltages as a function of the battery voltage, maximum current data representing the maximum level of test currents as a function of battery charge capacity, and fault data representing predetermined battery fault conditions as a function of battery voltage;
said data processing means being further programmed to control said energizing means during a test cycle to supply a test current having gradually increasing and decreasing portions and to obtain a dynamic voltage-current characteristic as a function of said supplied current and the voltage across said battery sensed by said sensing means while said current is supplied;
said data processing means being further programmed to determine the number of cells included in said battery as a function of said sensed voltage when said current is substantially zero;
said data processing means being further programmed to determine the slope of said dynamic voltage-current characteristic and to derive the charge capacity of said battery as a function of the determined number of cells and determined slope;
said data processing means being further programmed to compare said sensed voltage when said current is substantially zero to said stored charge level data to derive the charge level of said battery;
said data processing means being further programmed to compare said obtained dynamic voltage-current characteristic to said fault data to indicate the presence of a battery fault condition;
said data processing means being further programmed to control said energizing means during a charge cycle to supply a charging voltage to said battery in accordance with said stored charging voltage data, dependent upon said battery voltage sensed during said test cycle, and said derived charge level of said battery; and
said data processing means being further programmed to compare the latest dynamic voltage-current characteristic obtained with the preceding dynamic voltage-current characteristic and to terminate further charge cycles when the compared characteristics are substantially identical.
- sensing means coupled to said battery to sense voltage thereacross; and
Specification