Battery charger and power reduction system and method

• US 20070069690A1
• Filed: 09/26/2005
• Published: 03/29/2007
• Est. Priority Date: 09/26/2005
• Status: Active Grant

• Current Assignee: U.S. Govt., As Represented by The Dept., of the Navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Hand, Evan
• Granted Patent: US 7,573,235 B2
• Time in Patent Office: Days
• US Class Current: 320/128
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits

Abstract

The present invention is a shunt-type, battery-charging device that (through the use of a power dissipation and/or power reduction system and/or method) is designed to reduce the likelihood of overcharging and the possible deleterious effects (and cooling requirements) associated with the generation of heat during the charging process. Generally, the power reduction system and/or method may control the amount of power being used by the battery charger by monitoring the batteries'"'"' level of charge during charging, and by correspondingly reducing the magnitude of the charging current in response to such monitored level.

Claims

1. A battery charging apparatus for charging at least one rechargeable battery, the apparatus comprising:

a current source for providing a charging current to said at least one rechargeable battery;

at least one shunt-type charging circuit in electrical communication with said current source, wherein each said at least one shunt-type charging circuit is capable of;

(a) sensing the charging level of said at least one rechargeable battery; and

(b) forming and transmitting a charging level output signal; and

a current source controlling means in electrical communication with each of said at least one shunt charge circuit and with said current source, wherein said current source controlling means is capable of receiving each said charging level output signal, and wherein said current source controlling means is capable of forming and transmitting a current source control signal for controlling the magnitude of said charging current.

2. The battery charging apparatus as recited in claim 1, wherein said charging apparatus further comprises at least one battery charging slot in electrical communication with said current source, wherein each of said at least one battery charging slot is capable of operationally holding one of said at least one rechargeable battery.

3. The battery charging apparatus as recited in claim 1, wherein said current source is programmable.

4. The battery charging apparatus of claim 3, wherein said current source is capable of receiving said current source control signal and is programmed to modify the magnitude of said charging current based on said current source control signal.

5. The battery charging apparatus of claim 1, wherein each shunt-type charging circuit further comprises a voltage comparator.

6. The battery charging apparatus of claim 1, wherein each shunt-type charging circuit further comprises a current sensor for forming and transmitting said charging level output signal to said current source controlling means.

7. The battery charging apparatus of claim 1, wherein said current source controlling means is a computing device.

8. The battery charging apparatus of claim 7, wherein said computing device further comprises an analog-to-digital input device in electrical communications with each of said at least one shunt-type charging circuit for receiving and processing each said charging level output signal.

9. The battery charging apparatus of claim 8, wherein said computing device further comprises, a digital-to-analog output device in electrical communications with said analog-to-digital input device for receiving and processing signals from said analog-to-digital input device, and for forming and transmitting said current source control signal.

10. The battery charging apparatus of claim 9, wherein said computing device further comprises a control algorithm for controlling said control signal for controlling the magnitude of said charging current.

11. The battery charging apparatus of claim 1, wherein said current source is at least one solar cell.

12. The battery charging apparatus of claim 11, wherein said current source controlling means is comprised of a computing device, and wherein said computing device is comprised of an analog-to-digital input device;

a switch output controller;

a control algorithm; and

a switch control matrix in electrical communications with said switch output controller and said at least one solar cell, said switch output controller capable of generating and transmitting said current source control signal.

13. The battery charging apparatus of claim 12, wherein said switch control matrix is capable of receiving and processing said current source control signal from said switch output controller, and wherein said switch control matrix controls the magnitude of said charging current by adjusting the number of said at least one solar cell being used to supply said charging current.

14. The battery charging apparatus of claim 1, wherein said current source is at least one solar array.

15. The battery charging apparatus of claim 14, wherein said current source controlling means is comprised of a computing device, and wherein said computing device is comprised of an analog-to-digital input device;

a switch output controller;

a control algorithm; and

a switch control matrix in electrical communications with said switch output controller and said at least one solar array, said switch output controller capable of generating and transmitting said current source control signal.

16. The battery charging apparatus of claim 15, wherein said switch control matrix is capable of receiving and processing said current source control signal from said switch output controller, and wherein said switch control matrix controls the magnitude of said charging current by adjusting the number of said at least one solar array being used to supply said charging current.

17. A battery charging apparatus, said apparatus comprising:

a programmable current source for providing a charging current to at least one rechargeable battery;

a charging circuit in parallel electrical connection to said programmable current source, wherein said charging circuit (a) detects that said at least one rechargeable battery is in operational electrical communications with said battery charging apparatus, (b) determines whether said charging circuit is actively charging said at least one rechargeable battery, and (c) determines the magnitude of a bypass current bypassing said at least one rechargeable battery; and

a controller comprised of a power reduction algorithm for controlling the magnitude of said charging current provided by said programmable current source, wherein said controller is in electrical communication with said charging circuit and said programmable current source, and wherein said power reduction algorithm analyzes;

(a) the magnitude of said charging current;

(b) whether said charging circuit is actively charging said at least one rechargeable battery; and

(c) the magnitude of said bypass current bypassing said at least one rechargeable battery;

wherein, based on said power reduction algorithm analysis, said controller adjusts the magnitude of said charging current in response to changes in said bypass current.

18. The battery charging apparatus as recited in claim 17, wherein said charging apparatus further comprises at least one battery charging slot in electrical communication with said programmable current source, wherein each of said at least one battery charging slot is capable of operationally holding at least one of said at least one rechargeable battery and enabling each of said at least one rechargeable battery to receive said charging current from said programmable current source.

19. A power reduction method for use with a shunt-type battery charger, comprising the steps of:

a. Activating a shunt-type battery charger;

b. Utilizing a programmable controller for generating at least one control signal based on;

the magnitude of a charging current;

(b) whether at least one rechargeable battery is actively being charged; and

(c) the magnitude of a bypass current bypassing said at least one rechargeable battery; and

c. Utilizing a power reduction algorithm for analyzing said at least one control signal, and for adjusting the magnitude of said charging current in response to changes in the magnitude of said bypass current.