BATTERY POWER SUPPLY, MAINTENANCE FREE

• US 3,796,940 A
• Filed: 12/27/1971
• Issued: 03/12/1974
• Est. Priority Date: 12/27/1971
• Status: Expired due to Term

• Current Assignee: Robert E. Mauch, Robert I. Sarbacher
• Original Assignee: Robert E. Mauch, Robert I. Sarbacher
• Inventors: Mauch, Robert E., Sarbacher, Robert I.
• Primary Examiner(s): Duggan, D. F.
• Assistant Examiner(s): Hickey, Robert J.
• Application Number:
  US05/212,178
• Time in Patent Office: 806 Days
• Field of Search: 320/14,21,43-45 307/37,38,66,43,46,48-50
• US Class Current: 320/119
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current

Abstract

A power supply which automatically provides the necessary maintenance cycling for secondary batteries according to a predetermined schedule is disclosed. The power supply is designed to eliminate the detrimental effects of long idle periods during which the battery is not used. This system will, at a predetermined time, or at the end of a predetermined period, cause the battery to go through a discharge-charge cycle. Several embodiments of the invention are disclosed.

Claims

1. A battery power supply automatic maintenance cycling system comprising:

a battery normally coupled across a battery charger;

a coulometer for measuring time coupled to said battery;

a dummy load; and

means responsive to said coulometer for automatically uncoupling said battery from said battery charger after a predetermined period of time and coupling said battery to said dummy load to discharge said battery and then uncoupling said battery from said dummy load and recoupling said battery to said battery charger after said battery has been discharged for a predetermined period of time that is measured by said coulometer.

2. A battery power supply automatic maintenance cycling system as defined in claim 1 wherein a constant current regulator is connected in series with said coulometer.

3. A battery power supply automatic maintenance cycling system as defined in claim 2 wherein said means responsive to said coulometer includes a voltage responsive switch coupled to said battery, said battery charger and said dummy load such that said batterY is coupled to said dummy load as long as a voltage is applied to said switch and is coupled to said battery charger when no voltage is applied to said switch.

4. A battery power supply automatic maintenance cycling system as defined in claim 3 wherein said coulometer provides a first voltage when said battery has been coupled across said battery charger for a predetermined period and a second voltage when said battery has been coupled across said dummy load for a predetermined period of time and wherein sensing and reset means are coupled between said coulometer and said switch to provide a voltage to said switch to uncouple said battery from said battery charger and couple said battery to said dummy load in response to said first coulometer voltage and to remove said voltage from said switch in response to said second coulometer voltage to recouple said battery to said battery charger.

5. A battery power supply automatic maintenance cycling system as defined in claim 4 wherein no power is available to an external load during the time said battery is coupled to said dummy load.

6. A battery power supply automatic maintenance cycling system as defined in claim 5 wherein at least one additional battery is connected in parallel with said battery.

7. A battery power supply automatic maintenance cyling system comprising:

a first battery normally coupled to a battery charger;

a second battery normally coupled to said battery charger;

time measuring means coupled to said first battery and said second battery;

a first dummy load;

a second dummy load; and

means responsive to said time measuring means for automatically uncoupling said first battery from said battery charger after a predetermined period of time and coupling said first battery to said first dummy load to discharge said frist battery and then uncoupling said first battery from said first dummy load and recoupling said first battery to said battery charger after said first battery has been discharged for a predetermined period of time that is measured by said time measuring means, and for automatically uncoupling said second battery from said battery charger a predetermined period of time after said first battery is recoupled to said battery charger and coupling said second battery to said second dummy load to discharge said second battery and then recoupling said second battery to said battery charger after said second battery is discharged and then after another predetermined period of time again uncoupling said first battery from said battery charger and coupling said first battery to said first dummy load to discharge said first battery and then recoupling said first battery to said battery charger after said first battery is discharged and then after still another period of time repeats the steps of uncoupling said second battery from said charger and coupling it to said second dummy load and then back to said charger whereby said first battery and said second battery are alternately discharged and charged periodically.

8. A battery supply automatic maintenance cycling system as defined in claim 7 wherein said means responsive to said time measuring means comprises a sequencing switch and sensing and reset means coupled to said time measuring means.

9. A battery power supply automatic maintenance cycling system as defined in claim 8 wherein said time coulometer means comprises a coulometer and constant current regulator coupled in series across said battery.

10. A battery power supply automatic maintenance cycling system as defined in claim 9 wherein more than two batteries normally coupled across said battery charger are provided and a number of dummy loads equal in number to the total number of batteries is provided and wherein all said batteries provided are alternately, one at a time, uncoupled from said battery charger, coupled to their respective loads for discharge and then recoupled to said battery charger.

11. A battery power supply automatic maintenance cycliNg system comprising:

a battery having a plurality of cells coupled in series to a battery charger;

time measuring means coupled to said battery;

a dummy load; and

means responsive to said time measuring means for automatically uncoupling all of said cells, alternately, one at a time, from said charger and coupling the one cell uncoupled from said charger at that time to said dummy load to discharge that said cell then recoupling this said cell to said battery charger whereby all of said cells are alternately discharged and charged one at a time.

12. A battery power supply automatic maintenance cycling system as defined in claim 11 wherein said means responsive to said time measuring means includes a sequencing switch coupled to said time measuring means.

13. A battery power supply automatic maintenance cycling system as defined in claim 12 wherein said time measuring means comprises a coulometer and constant current regulator coupled across all of said cells.

14. A battery power supply automatic maintenance cycling system as defined in claim 13 wherein a discharge monitor is coupled to said dummy load and wherein an indicator for indicating a defective cell is coupled to said discharge monitor.

15. A battery power supply automatic maintenance cycling system as defined in claim 14 wherein power is available to an external load at all times including the times at which a cell is being discharged.

16. A battery power supply automatic maintenance cycling system as defined in claim 15 wherein terminals are provided for connecting a number of said cells to an external load and wherein cell switching means are provided to vary the number of said cells coupled to said terminals so that a predetermined voltage is available to said external load, said cell switching means being so designed that one or more cells are automatically added to the number of cells then coupled to said terminals when one or more cells become defective, the number of cells added being equal in number to the number of defective cells, said cell switching means responding to a cell under discharge as being a defective cell during discharge, whereby said predetermined voltage is available to said external load at all times.