Battery charger termination circuit
First Claim
1. In a method for charging a storage battery wherein the battery is initially charged at a maximum rate of current which tapers in magnitude until the battery attains a preselected voltage, and is thereafter charged at reduced rate of current which tapers in magnitude during finishing portions of said charging, the improvement wherein the method further comprises the steps of:
- (a) monitoring the current delivered to the battery during said charging, thereby developing data defining a curve representative of current delivered to the battery over time;
(b) monitoring the slope of said curve during charging; and
(c) terminating the charging process when a pre-selected slope value in a range between approximately -2.0 and -0.5 amperes per 100 ampere hours per hour is attained.
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Accused Products
Abstract
A system for charging a storage battery initially charges the battery at a maximum rate of current which tapers in magnitude until the battery attains a selected voltage, and thereafter charges the battery with a continuing reduction of current until termination. Termination is accomplished by sensing current delivered to the battery over time, monitoring a curve representative of such data, and discontinuing charger operation when the slope of the curve attains a selected value.
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Citations
17 Claims
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1. In a method for charging a storage battery wherein the battery is initially charged at a maximum rate of current which tapers in magnitude until the battery attains a preselected voltage, and is thereafter charged at reduced rate of current which tapers in magnitude during finishing portions of said charging, the improvement wherein the method further comprises the steps of:
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(a) monitoring the current delivered to the battery during said charging, thereby developing data defining a curve representative of current delivered to the battery over time; (b) monitoring the slope of said curve during charging; and (c) terminating the charging process when a pre-selected slope value in a range between approximately -2.0 and -0.5 amperes per 100 ampere hours per hour is attained. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. In an apparatus for charging a storage battery wherein the battery is initially charged at a maximum rate of current which tapers in magnitude until the battery attains a pre-selected voltage, and is thereafter charged at a reduced rate of current which tapers in magnitude during finishing portions of said charging, the improvement which further comprises:
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(a) means for monitoring the current delivered to the battery during said charging, thereby developing data defining a curve representative of current delivered to the battery over time, said current monitoring means comprising; (i) shunt means placed in series electrical connection with said battery, to develop an analog signal indicative of current delivered to the battery; and (ii) means coupled to said shunt means for converting said analog signal to a digital signal; (b) means for monitoring the slope of said curve during charging, said slope monitoring means comprising; (i) counter means coupled to said current monitoring means, for producing a digital representation proportional to the output of said current monitoring means; (ii) shift register means coupled to said counter means and adapted to store data representative of the current being delivered to said battery; (iii) outer means coupled to said counter means and adapted to develop data representative of the current being delivered to said battery and an offset representative of a selected slope value; and (iv) comparison means coupled to said shift register means and said outer means, for comparing data stored in said shift register means with offset data developed in said outer means; and (c) means for terminating said charging in accordance with the slope of said curve. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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Specification