Electronic battery charger device and method
First Claim
1. A device for charging one or more batteries comprising a circuit having terminal means for connecting to the terminal means on one or more batteries to be charged, said circuit including a source of electric energy, controllable switching means connected respectively between the energy source and each battery to be charged, a microprocessor having a control connection to each of the controllable switching means for controlling communication between the energy source and the respective batteries to be charged, said microprocessor including means to sequentially control the switch means to supply charging current to the batteries one at a time in repeating periods, means responsive to the voltage across the terminals of each battery prior to and during each charging period thereof operatively connected to the microprocessor, said microprocessor being programmed to calculate the difference between the battery terminal voltage of each battery prior to and when it is being charged, means to store for each battery the minimum value of said voltage difference during each charging period, and means to terminate a charging operation for a battery when the battery terminal voltage difference being calculated exceeds the minimum stored value of the battery terminal voltage difference by a predetermined amount.
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Accused Products
Abstract
A battery charger device and method including a charging circuit having a source of charging energy and connections for installing one or more batteries to be charged, the device having a controllable switch associated with each battery to be charged and a microprocessor for controlling the switches to establish a charging sequence of distinct repeated charging periods for each battery, a display device associated with each battery under control of a microprocessor for individually indicating the charging status of each battery, the microprocessor having inputs at which various parameters with respect to the batteries being charged are applied such as battery voltages, ambient temperatures and charging currents, the microprocessor being programmed to terminate a voltage charging operation with respect to any one or more of the batteries if the measured difference between the charging and non charging voltage of any one or more of the batteries during succeeding charging periods exceeds some predetermined value, or if the charging current, or the ambient temperature of the battery being charged is outside of a predetermined range. The present device and method may also include a back up termination means which responds to measurements of the battery voltage during succeeding charging periods and determines therefrom that on a predetermined number of succeeding cycles the condition of the battery voltage has changed by at least some predetermined amount.
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Citations
50 Claims
- 1. A device for charging one or more batteries comprising a circuit having terminal means for connecting to the terminal means on one or more batteries to be charged, said circuit including a source of electric energy, controllable switching means connected respectively between the energy source and each battery to be charged, a microprocessor having a control connection to each of the controllable switching means for controlling communication between the energy source and the respective batteries to be charged, said microprocessor including means to sequentially control the switch means to supply charging current to the batteries one at a time in repeating periods, means responsive to the voltage across the terminals of each battery prior to and during each charging period thereof operatively connected to the microprocessor, said microprocessor being programmed to calculate the difference between the battery terminal voltage of each battery prior to and when it is being charged, means to store for each battery the minimum value of said voltage difference during each charging period, and means to terminate a charging operation for a battery when the battery terminal voltage difference being calculated exceeds the minimum stored value of the battery terminal voltage difference by a predetermined amount.
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20. A battery charger device comprising
a circuit having terminal means for connecting to terminals of batteries to be charged, said circuit including a source of charging energy and separate switch means for connecting said energy source to each battery to be charged, means including microprocessor means connected to said switch means to control electrical communication between the energy source and the respective batteries, means in the microprocessor for producing a sequence of distinct charging intervals for the batteries when the respective switch means are closed and the associated batteries are charging separated by non charging intervals when the switch means are open, means for reading the battery terminal voltage of each battery prior to and during each of its charging intervals, means for computing the difference between the battery terminal voltage prior to and during each succeeding charging interval for each battery to be charged, means for storing a value representing the minimum value of the difference between the terminal voltage prior to and during each charging interval, including means for comparing the stored minimum value of the voltage difference with each computed value thereof for each battery during each battery charging operation and replacing the stored minimum value with each subsequent computed value that is less than the stored minimum value, and means to terminate a battery charging operation for a battery when the ratio of the computed voltage difference to the stored minimum value of the difference exceeds some predetermined amount.
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31. A battery charger device having means for charging a plurality of the same or of different type batteries such that all batteries of the same type are charged at substantially the same fast charging rate during predetermined equal length repeating time periods comprising
a circuit having a plurality of connection means for connecting to the terminals of batteries to be charged, a source of charging energy, separate switch means connected between the energy source and each battery and operable between an open non charging condition and a closed charging condition permitting substantially the same fast charging current from the energy source to pass through the associated battery during each equal length repeating charging period thereof, microprocessor means including means for controlling the condition of the switch means, means to establish predetermined equal length repeating charging periods for each battery, means to establish a charging sequence whereby each of said plurality of batteries in order has distinctive spaced equal length time subperiods when it is being charged followed by a non charge interval, separate means associated with each battery responsive to battery terminal voltage, battery current, and battery ambient temperature connected to the microprocessor, and means in the microprocessor for terminating a battery charging operation with respect to any one or more of the plurality of batteries if any one or more of the following occur, the battery voltage of the battery whose charge is to be terminated equals or exceeds for that battery a first predetermined voltage, equals or is less than a second predetermined voltage, if the battery charging current for that battery equals or exceeds a predetermined current, or if the ambient temperature of the battery equals or exceeds a first predetermined temperature or equals or is less than a second predetermined temperature.
- 35. Apparatus for fast charging a battery comprising a circuit having a power supply including a portion for supplying charging current to a battery being charged, said power supply portion including means to select between supplying a fast charge current or a trickle charge current to the battery, controllable switch means connected between the power supply portion and the battery, control circuit means operatively connected to the switch means to close and open the switch means to establish a charging and a non charging condition, program means for establishing a series of time spaced charging and non charging conditions, means to establish a predetermined overall time period for charging the battery when applying a fast charge current, means to read the battery terminal voltage for each battery prior to and during each fast charging condition, means to calculate the absolute value of the difference between these battery terminal voltages for each charging condition, means during each overall time period for storing the minimum value of the calculated difference including means to replace a previously stored value with each newly read and calculated value that is less than the previously stored minimum value, means to compute the ratio of each newly calculated value of the voltage difference to the minimum stored value thereof including means to terminate a fast charge condition when the ratio is greater than some predetermined value.
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47. A method of rapidly and efficiently charging one or more than one batteries of a type in which the voltage characteristics thereof varies with the state of charge of the battery comprising the steps of:
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connecting one or more batteries to be charged to a battery charger that includes means for supplying electrical energy for charging the batteries, establishing a time sequence for supplying energy to each of the batteries one at a time in time-spaced intervals so that each battery undergoes periodic charging and non charging intervals, reading the voltage across each battery being charged prior to and during each charging interval thereof, computing the difference between the battery voltage read prior to and during each succeeding charging interval for each battery, storing the value of the said calculated voltage difference between the battery voltage prior to and the battery voltage during each succeeding charging interval including updating the stored difference voltage when the calculated difference voltage is less than the value previously stored, and terminating a battery charging operation for a battery when the ratio of the present value of the computed voltage difference therefor to the stored minimum value of the voltage difference for said battery exceeds a predetermined ratio. - View Dependent Claims (48, 49)
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50. A battery charger device having means for charging a plurality of batteries over a predetermined time period comprising
a circuit having a plurality of connection means for connecting to the terminals of batteries to be charged, a source of charging energy, a separate switch means connected between the energy source and each battery and operable between an open non charging condition and a closed charging condition permitting charging current from the energy source to pass through the associated battery, microprocessor means including means for controlling the condition of the switch means, means to establish a predetermined charging period, means to establish a charging sequence whereby each of said plurality of batteries in order has distinctive spaced timed subperiods when it is being charged followed by a non charge interval, separate means associated with each battery responsive to battery terminal voltage, battery current, and battery ambient temperature connected to the microprocessor, means in the microprocessor for terminating a battery charging operation with respect to any one or more of the plurality of batteries if any one or more of the following occur, the battery voltage of the battery whose charge is to be terminated equals or exceeds a first predetermined voltage, equals or is less than a second predetermined voltage, if the battery charging current equals or exceeds a predetermined current, or if the ambient temperature of the battery equals or exceeds a first predetermined temperature or equals or is less than a second predetermined temperature, and means in the microprocessor for computing the difference between the battery terminal voltage for each battery prior to and during each charging subperiod, means to store the computed voltage difference for each battery including means to replace the stored difference for each battery by a succeeding difference that is less than the previously stored difference, and means to terminate a charging operation with respect to a battery when the ratio of the computed voltage difference value to the stored minimum difference exceeds some predetermined amount.
Specification