Battery charger system

• US 5,646,507 A
• Filed: 10/03/1996
• Issued: 07/08/1997
• Est. Priority Date: 10/22/1993
• Status: Expired due to Fees

• Current Assignee: Douglas Battery Manufacturing Company
• Original Assignee: Douglas Battery Manufacturing Company
• Inventors: Stahl, Larry D., Boden, David P., Timmons, John B.
• Primary Examiner(s): TSO, EDWARD H
• Application Number:
  US08/728,132
• Time in Patent Office: 278 Days
• Field of Search: 320/5, 320/9, 320/4, 320/30, 320/43, 320/44, 320/45, 320/48, 320/21
• US Class Current: 320/149
• CPC Class Codes: B60L 2200/22 Microcars, e.g. golf cars
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 2200/42 Fork lift trucks
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 53/305 Communication interfaces
• CPC Class Codes: H01M 10/06 Lead-acid accumulators semi-lead accumulators H01M10/20
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles

Abstract

A direct current power source for powering an electric vehicle. The power source has a rechargeable battery and a battery charger control unit for providing a charge to the battery with an amount of electrical energy which corresponds to the amount of electrical energy discharged since the previous charge plus a selected additional amount of charge to slightly overcharge the battery during a full restoration. The battery charger control unit includes a charge monitor for determining the flow of electrical energy into and out of the battery and a charge controller for controlling a battery charger. In one embodiment, the battery and the battery charger control unit are integrated. In the preferred embodiment, the charge controller includes means for controlling the battery charger in accordance with the amount of electrical energy charged to and discharged from the battery as measured by the charge monitor. In addition, the charge controller may include means for controlling a function of the vehicle in accordance with the amount of electrical energy charged to and discharged from the battery as measured by the charge monitor.

Claims

1. An integrated direct current power source unit for powering an electric vehicle, comprising:

(a) battery charger;

(b) a rechargeable lead acid battery having positive and negative terminals; and

(c) a battery charger control unit for providing a charge from said battery charger to said battery with an amount of electrical energy less than required to fully charge said battery during a partial restoration and with an amount of electrical energy which corresponds to an effective sum of electrical energy withdrawn since a previous full charge plus a selected additional amount of energy to slightly overcharge said battery during a full restoration, said battery charger control unit comprising;

(i) a charge monitor coupled to said terminals of said battery for determining the total flow of electrical energy into and out of said battery during any partial discharge and charge cycles since a previous full charge, wherein said charge monitor includes means for measuring a parameter corresponding to the amount of electrical energy charged to and discharged from said battery; and

(ii) a charge controller for controlling the flow of electrical energy into said battery by said battery charger,

(d) said battery, charger and charger control unit integrated together and carried by the vehicle to provide said single direct current power source unit.

2. The power source of claim 1 wherein said battery and said battery charger control unit are integrated.

3. The power source of claim 1 wherein said battery charger is integrated with said battery charger control unit.

24. The apparatus of claim 1 wherein the energy is measured in ampere-hours and said selected additional amount of energy to slightly overcharge said battery, during a full restoration is a predefined percentage of said effective sum of energy withdrawn since a previous full charge measured in ampere-hours.

4. The power source of claim 1wherein said battery is of the type selected from the group consisting of valve regulated batteries, flooded antimonial batteries, and flooded calcium batteries.

5. The power source of claim 4 wherein said charge controller includes means for controlling a battery charger in accordance with the amount of electrical energy charged to and discharged from said battery as measured by said charge monitor.

6. The power source of claim 4 wherein said charge controller includes means for controlling a prescribed function of the vehicle in accordance with the amount of electrical energy charged to and discharged from said battery as measured by said charge monitor.

7. An electric vehicle, comprising:

(a) an electrically-powered motor means for moving the electric vehicle;

(b) an integrated power source carried by said vehicle comprising;

(i) a rechargeable battery having positive and negative terminals for providing electricity to said motor means;

(ii) a battery charger; and

(iii) a battery charger control unit for providing a charge from a battery charger to said battery with an amount of electrical energy less than required to fully charge said battery during a partial restoration and with an amount of electrical energy which corresponds to an effective sum of electrical energy withdrawn since a previous full charge plus a selected additional amount of energy to slightly overcharge said battery during a full restoration, said battery charger control unit comprising;

(A) a charge monitor coupled to said terminals of said battery for determining the total flow of electrical energy into and out of said battery during any partial discharge and charge cycles since the previous full charge;

wherein said charge monitor includes means for measuring a parameter corresponding to the amount of electrical energy charged to and discharged from said battery; and

(B) a charge controller for controlling the flow of electrical energy into said battery by said battery charger.

8. The electric vehicle of claim 7 wherein said battery and said battery charger control unit are integrated.

9. The electric vehicle of claim 7 wherein said battery charger and said battery charger control unit are integrated.

10. The power source of claim 7 wherein said battery is of the type selected from the group consisting of valve regulated batteries, flooded antimonial batteries, and flooded calcium batteries.

11. The electric vehicle of claim 7 wherein said charge controller is operative to calculate the state of charge of said battery and to control the charging of said battery by said battery charger in accordance with the state of discharge calculated.

12. The electric vehicle of claim 7 wherein said charge controller includes an actuating means to disable and enable a locomotive function of the vehicle when said charger is connected with an external power source.

25. The apparatus of claim 7 wherein the energy is measured in ampere-hours and said selected additional amount of energy to slightly overcharge said battery, during a full restoration is a predefined percentage of said effective sum of energy withdrawn since a previous full charge measured in ampere-hours.

13. A battery charger control unit integrated with a rechargeable lead acid battery having positive and negative terminals and a battery charger, comprising:

(a) a charge monitor coupled to said terminals of said battery for measuring the total electrical energy charged to and discharged from the battery during any partial discharge and charge cycles since a previous full charge, wherein said charge monitor includes means for measuring a parameter corresponding to the amount of electrical energy charged to and discharged from said battery;

(b) a charge controller for controlling the flow of electrical energy into the battery by the battery charger corresponding to an amount of energy less than required to fully charge said battery during a partial restoration and corresponding to an effective sum of electrical energy withdrawn since the previous full charge, plus a selected additional amount of energy to slightly overcharge said battery during a full restoration; and

(c) said charge controller including a charger actuator means for activating and deactivating the charger responsive to the charge condition of the battery.

14. The battery charger control unit of claim 13 wherein said charge controller further including calculator means for integrating the amount of electrical energy charged to and discharged from the battery over time, and wherein said charger actuator means is operative to activate the charger to charge the battery when the value of said integration is within a first selected range of values and is further operative to deactivate the charger when the value of said integration is within a second selected range of values.

15. The battery charger control unit of claim 14 wherein said charge controller is operative to control the charger such that the amount of electrical energy charged to the battery is equal to the amount of electrical energy discharged from the battery since the battery'"'"'s last charging, irrespective of the amount of that electrical energy.

16. The battery charger control unit of claim 14 further including signal actuating means for controlling a signal device, wherein said signal actuating means is operative to activate and deactivate the signal device when the value of said integration is within selected ranges of values.

17. The battery charger control unit device of claim 14 further including function actuating means for controlling a function of an associated vehicle, wherein said function actuating means is operative to activate and deactivate said function when the value of said integration is within a selected range of values.

18. The battery charger control unit of claim 17 wherein said function is a locomotive feature and said function actuating means is further operative to disable and enable said locomotive feature when the battery is connected with an external power source cord.

19. The battery charger control unit of claim 17 wherein said associated vehicle is a forklift truck, and wherein said function is a lift function of said forklift truck, and wherein said function actuating means is operative to disable and enable said lift function.

20. The battery charger control unit of claim 13 further including manual control means, wherein said charger actuating means is operative to activate the charger to deliver a selected amount of charge to the battery when said manual control means is actuated.

26. The apparatus of claim 13 wherein the energy is measured in ampere-hours and said selected additional amount of energy to slightly overcharge said battery, during a full restoration is a predefined percentage of said effective sum of energy withdrawn since a previous full charge measured in ampere-hours.

21. A method for automatically charging a battery having positive and negative terminals using a battery charger and a battery charger control unit, the battery charger control unit including a charge monitor and a charge controller, comprising the steps of:

(a) measuring at the terminals of the battery the total amount of electrical energy discharged from and charged to the battery during partial discharge and charge cycles since a previous full charge using the charge monitor;

(b) calculating a sum total of energy discharged from the battery according to measurements from the first step;

(c) inputting from the charge monitor to the charge controller a value corresponding to the sum of electrical energy measured in the calculating step;

(d) adding to the value a selected additional amount corresponding to a select amount of overcharging when fully charging the battery; and

(e) controlling the charger using the charge controller such that the charger operates to slightly overcharge the battery.

22. The method of claim 21 wherein the reference value is the sum of the value inputted and an initial value corresponding to the sum total of energy discharged from the battery.

27. The method of claim 21 wherein the value corresponds to energy measured in ampere-hours and the selected additional amount corresponding to a select amount of overcharging corresponds to a predefined percentage of the sum total of energy discharged from the battery.

23. A method for automatically charging a battery having positive and negative terminals using a battery charger and a battery charger control unit, the battery charger unit including a charge monitor and a charge controller, comprising the steps of:

(a) measuring at the terminals of the battery the rate of charge to and the rate of discharge from the battery using the charge monitor during partial discharge and charge cycles since a previous full charge;

(b) inputting measurements obtained in the preceding step to the charge controller;

(c) integrating the measurements to obtain a charge state value; and

(d) controlling the charger by means of the charge controller to charge the battery by an amount of the charge state value plus a selected additional amount to slightly overcharge said battery.

28. The method of claim 23 wherein the charge state value corresponds to an amount of energy in ampere-hours and the selected additional amount corresponds to a predefined percentage the charge state value.