TERMINATION OF RAPID CHARGING OF BATTERIES

• US 3,609,503 A
• Filed: 10/20/1969
• Issued: 09/28/1971
• Est. Priority Date: 10/20/1969
• Status: Expired due to Term

• Current Assignee: Robert V. Jackson, Wilford B. Burkett
• Original Assignee: Robert V. Jackson, Wilford B. Burkett
• Inventors: Burkett, Wilford B., Jackson, Robert V.
• Primary Examiner(s): Miller, J. D.
• Assistant Examiner(s): Gunther, John M.
• Application Number:
  US04/870,402
• Time in Patent Office: 708 Days
• Field of Search: 320/DIG.2,DIG.1,4,5,14,21-24,39,40,35,36
• US Class Current: 320/129
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process
• CPC Class Codes: Y10S 320/17 Sensing of "gassing" voltage

Abstract

A battery is charged rapidly by alternately applying a charging current to the battery and selectively discharging the battery. During this rapid charging operation, the magnitude of charge on the battery is determined by monitoring terminal characteristics of the battery. When the monitored terminal characteristic of the battery reaches a predetermined value, the rapid charging operation is either manually or automatically terminated. Such terminal characteristics as average discharge current, energy release during a discharge interval, terminal voltage of the battery an increment of time after the start of the discharge interval, and the frequency of the discharge interval are monitored.

Claims

1. A method comprising the steps of:

rapid charging a battery by imposing an increasing charge on the battery by charging the battery during a plurality of charging intervals, and providing battery discharge intervals interspersed with said charging intervals; and

causing the duration of intervals of said charging to diminish as said charge in said battery increases;

monitoring a terminal characteristic of the battery during the rapid charging step; and

terminating the rapid charging step when the monitored terminal characteristic of the battery assumes a predetermined value.

2. A method comprising the steps of:

rapid charging a battery by charging the battery during a plurality of charging intervals, and providing battery discharge intervals interspersed with said charging intervals;

causing the frequency of said discharging intervals to increase as said charge on said battery increases;

monitoring a terminal characteristic of the battery during the rapid charging step; and

terminating the rapid charging step when the monitored terminal characteristic of the battery assumes a predetermined value.

3. A method comprising the steps of:

rapid charging a battery by imposing an increasing charge on the battery by charging the battery during a plurality of charging intervals, and discharging the battery during discharging intervals interspersed with said charging intervals, effecting said charging with charge current exceeding the nominal one-hour rate of the cells of said battery; and

by maintaining the duration of each interval of charging as a function of a condition of said battery; and

in response to a predetermined battery condition, causing the duration of intervals of said charging to diminish as said charging and discharging progresses;

monitoring a terminal characteristic of the battery during the rapid charging step; and

terminating the rapid charging step when the monitored terminal characteristic of the battery assumes a predetermined value.

4. A method comprising the steps of rapid charging a battery by charging the battery during a plurality of charging intervals, and discharging the battery during discharging intervals interspersed with said charging intervals, effecting said charging with charge current exceeding the nominal one-hour rate of the cells of said battery;

maintaining the duration of each interval of charging as a function of a condition of said battery;

in response to a predetermined battery condition, causing the frequency of said discharging intervals to increase as said charging and discharging progresses as said battery increases;

monitoring a terminal characteristic of the battery during the rapid charging step; and

terminating the rapid charging step when the monitored terminal characteristic of the battery assumes a predetermined value.

5. A method comprising the steps of:

rapid charging a battery by charging the battery during a plurality of charging intervals, and providing battery discharge intervals interspersed with said charging intervals;

causing the frequency of said discharging intervals to increase as said charge on said battery increses;

causing the duration of intervals of said charging to diminish as said charge on said battery increases; and

causing the quotient of the duration of a charging interval divided by the duration of a succeeding discharging interval to diminish as said charge on said battery increases;

monitoring a terminal characteristic of the battery during the rapid charging step; and

terminating the rapid charging step when the monitored terminal characteristic of the battery assumes a predetermined value.

6. A method comprising the steps of:

rapid charging a battery by charging the battery during a plurality of charging intervals, and discharging the battery during discharging intervals interspersed with said charging intervals, effecting said charging with charge current exceeding the nominal one-hour rate of the cells of said battery;

maintaining the duration of each interval of charging as a function of a condition of said battery;

in response to a predetermined battery condition causing the frequency of the intervals of discharging to increase as said charging and discharging progresses;

in response to said predetermined battery condition, causing the duration of intervals of said charging to diminish as said charging and discharging progresses; and

in response to said predetermined battery condition, causing the quotient of the duration of a charging interval divided by the duration of a succeeding discharging interval to diminish as said charging and discharging progresses;

monitoring a terminal characteristic of the battery during the rapid charging step; and

terminating the rapid charging step when the monitored terminal characteristic of the battery assumes a predetermined value.

7. A method of rapid charging batteries comprising the steps of:

applying a charging current at an optimum rate for the size, structure, and materials of the battery, whereby the parameters of terminal voltage, pressure, and temperature of the battery change;

sensing the change in one of the parameters;

interrupting the charging current and depolarizing the battery by discharging at a high rate in response to the occurrence of a preselected value in the sensed parameter;

monitoring a terminal characteristic of the battery; and

repeating the above steps until the monitored terminal characteristic of the battery assumes a predetermined value.

8. A circuit arrangement comprising:

a source of charging current;

a battery to be charged;

means for sensing the change in the voltage, temperature, or pressure of the battery during charge;

means responsive to the occurrence of a preselected value of the sensed parameter for interconnecting the source and the battery so as to alternately apply charging current from the source to the battery and to depolarize the battery;

a switch connected between the source and the battery such that when the switch is closed the battery is alternately charged and depolarized through the interconnecting means and when the switch is open the charging source is out of circuit with the battery;

means for sensing a terminal characteristic of the battery; and

means responsive to the sensing means for opening the switch when the sensed terminal characteristic of the battery assumes a predetermined value.

9. The circuit arrangement of claim 8, in which the interconnecting means depolarizes the battery by dischaRging it.

10. The circuit arrangement of claim 8, in which the sensing means senses the average discharge current of the battery.

11. The circuit arrangement of claim 8, in which the sensing means senses the energy released from the battery during discharge.

12. The circuit arrangement of claim 11, in which the predetermined value of the energy released by the battery during discharge is a selected percentage of the energy put into the battery during the adjacent charging interval.

13. The circuit arrangement of claim 12, in which the sensing means is a bridge circuit connected in series with the battery, first and second diodes form two legs of the bridge circuit;

first and second resistance-capacitance circuits form the other two legs of the bridge circuit;

the junction of the first and second diodes and the junction of the first and second resistance-capacitance circuits are connected in series with the battery;

the first diode is poled such that the first resistance-capacitance circuit charges while charging current is applied through the interconnecting means to the battery;

the second diode being poled such that the second resistance-capacitance circuit charges while the battery is discharged through the interconnecting means; and

the means for opening the switch is responsive to the voltage between the junction of the first diode and the first resistance-capacitance circuit and the junction of the second diode and second resistance-capacitance circuit.

14. The circuit arrangement of claim 13, in which a resistor is provided having end terminals and an intermediate terminal, one end terminal of the resistor is connected to the junction of the first diode and the first resistance-capacitance circuit, the other end terminal of the resistor is connected to the junction of the second diode and the second resistance-capacitance circuit, and the means for opening the switch is responsive to the voltage between the intermediate terminal of the resistor and the junction of the first and second resistance-capacitance circuits.

15. The circuit arrangement of claim 14, in which the resistor is a potentiometer and the intermediate terminal is movable between the end terminals of the potentiometer.

16. The circuit arrangement of claim 8, in which the means for opening the switch is responsive to the terminal voltage of the battery a certain interval of time after the start of discharge.

17. The circuit arrangement of claim 8, in which the means for opening the switch is responsive to the frequency of the discharge of the battery.

18. A circuit arrangement comprising a circuit for rapidly charging a battery by alternately applying charge current at a rate in excess of the normal one-hour rate of the cells of the battery and discharging the battery, the rapid charging circuit comprising a direct-current source for supplying charging current coupled to the battery to be charged, means associated with the battery for sensing the change in one of the parameters of the battery that varies during the application of charging current, and means responsive to the sensing means for applying a discharge path across the battery for an interval of time between the application of charge current to the battery;

means for sensing a terminal characteristic of the battery, and means responsive to the terminal-characteristic sensing means to terminate the rapid charging of the battery.

19. A method comprising the steps of rapid charging a battery by imposing an increasing charge on the battery by applying a charging current in excess of the nominal one-hour rate of the cells of the battery, and intermittently discharging the battery with the discharging becoming more frequent with time;

monitoring a terminal characteristic of the battery during the rapid charging step; and

terminating the rapid charging step when the monitored terminal characteristic of the battery assumes a predetermined value.

20. The method of claim 19 in which the moNitored terminal characteristic is the average current during discharge.

21. The method of claim 19 in which the monitored terminal characteristic is the energy released from the battery during discharge.

22. The method of claim 21 in which the predetermined value of the energy released by the battery during discharge is a preselected percentage of the energy put into the battery during the application of the charging current thereto during the preceding charge interval.

23. The method of claim 1 in which the monitored terminal characteristic is the terminal voltage of the battery a predetermined time after the start of each discharging of the battery during the rapid charge step.

24. The method of claim 19 in which the monitored terminal characteristic is the frequency of discharging of the battery.

25. A method comprising the steps of charging a battery by applying a charging current above a first selected level to the battery whereby the parameters of terminal voltage, temperature, and pressure of the battery change;

sensing the change in one of the parameters, and intermittently, in response to the attainment of a preselected value of the sensed parameter, depolarizing the battery by reversing the current through the battery;

monitoring a terminal characteristic of the battery during the charging step; and

terminating the charging step when the monitored terminal characteristic of the battery assumes a predetermined value.

26. The method of claim 25 in which the monitored terminal characteristic is the average current during depolarization.

27. The method of claim 25 in which the monitored terminal characteristic is the energy released from the battery during depolarization.

28. The method of claim 27 in which the predetermined value of the energy released by the battery during depolarization is a preselected percentage of the energy put into the battery during the application of the charging current thereto during the preceding charge interval.

29. The method of claim 25 in which the monitored terminal characteristic is the terminal voltage of the battery a preselected increment of time after the start of each depolarizing of the battery during the charging step where the charging current is above the first selected level.

30. The method of claim 25 in which the monitored terminal characteristic is the frequency of depolarizing of the battery.

31. A method comprising the steps of rapid charging a battery by alternately charging with a charge current exceeding the nominal one-hour rate of the cells of the battery and discharging the battery to attain an increasing charge on the battery;

monitoring a terminal characteristic of the battery during the rapid charging step; and

terminating the rapid charging step when the monitored terminal characteristic of the battery assumes a predetermined value.