Battery charge detecting variable loads

• US 6,150,823 A
• Filed: 10/29/1992
• Issued: 11/21/2000
• Est. Priority Date: 12/11/1989
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Takahashi, Koji, Saeki, Takayuki, Takimoto, Hiroyuki, Tobe, Kazumitsu, Harigaya, Isao
• Primary Examiner(s): BROWN, GLENN WARNER
• Application Number:
  US07/968,250
• Time in Patent Office: 2,945 Days
• Field of Search: 324/426, 324/427, 324/429, 324/431, 340/636, 320/106, 320/135
• US Class Current: 324/427
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing
• CPC Class Codes: G01R 31/386 using test-loads

Abstract

Device for detecting the charge condition of a battery which measures the first output of the battery when connected to the first load and the second output of the battery when connected to the second load, and performs a predetermined computation on the basis of both the first and second outputs of the battery to detect the charge condition of the battery. The charge condition of the battery can be very accurately detected.

Claims

1. A device for detecting a state of charge of a battery, comprising:

(A) measuring means for measuring a first output of the battery when connected to a first load and a second output of the battery when connected to a second load; and

(B) detecting means for performing a predetermined computation on the basis of both the first output of the battery and the second output of the battery to detect the state of charge of the battery.

2. A device according to claim 1, wherein said detecting means computes an open circuit voltage of the battery on the basis of both the first output of the battery and the second output of the battery and detects the state of charge of the battery by using a memory which memorized a relation between the open-circuit voltage of the battery and the state of charge of the battery.

3. A device according to claim 1, wherein the detecting means supplies the state of charge of the battery to a display portion which displays a remaining service time of the battery.

4. A device for detecting a state of charge of a battery, comprising:

(A) measuring means for measuring a first output of the battery when connected to a first load and a second output of the battery when connected to a second load; and

(B) detecting means for performing a predetermined computation on the basis of both the first output of the battery and the second output of the battery to detect the state of charge of the battery, wherein the detecting means corrects the state of charge of the battery on the basis of a reference data.

5. A device according to claim 4, wherein the detecting means computes an open-circuit voltage of the battery on the basis of both the first output of the battery and the second output of the battery and detects the state of charge of the battery by using a memory which memorized a relation between the open-circuit voltage of the battery and the state of charge of the battery.

6. A device according to claim 4, wherein the detecting means supplies the state of charge of the battery to a display portion which displays a remaining service time of the battery.

7. A device for detecting a state of charge of a battery, comprising:

(A) measuring means for measuring a first output of the battery when connected to a first load and a second output of the battery when connected to a second load;

(B) temperature compensation means for compensating the first output of the battery and the second output of the battery on the basis of a temperature condition; and

(C) detecting means for performing predetermined computation on the basis of both the first output of the battery and the second output of the battery to detect the state of charge of the battery, said first output of the battery and said second output of the battery are temperature-compensated by said temperature compensation means.

8. A device according to claim 7, wherein said detecting means computes an open-circuit voltage of the battery on the basis of both the first output of the battery and the second output of the battery and detects the state of charge of the battery by using a memory which memorized a relation between the open-circuit voltage of the battery and the state of charge of the battery.

9. A device according to claim 7, wherein the detecting means supplies the state of charge of the battery to a display portion which displays a remaining service time of the battery.

10. A device for detecting a state of charge of a battery, comprising:

(A) measuring means for measuring a first output of the battery when a system connected to the battery is in a first operation mode and a second output of the battery when the system connected to the battery is in a second operation mode, said first operation mode and said second operation mode having a different load;

(B) detecting means for performing predetermined computation on the basis of both the first output of the battery and the second output of the battery to detect the state of charge of the battery; and

(C) compensation means for compensating the state of charge of the battery when one of the first and second operation modes continues for a predetermined period on the basis of consumption of the battery in the operation mode.

11. A device according to claim 10, wherein the state of charge of the battery is corrected when one of the first operation mode and the second operation mode continues for a predetermined period, and supplied to a display portion.

12. A device according to claim 11, wherein said detecting means computes an open-circuit voltage of the battery on the basis of both the first output of the battery and the second output of the battery and detects the state of charge of the battery by using a memory which memorized a relation between the open-circuit voltage of the battery and the state of charge of the battery.

13. A device according to claim 10, wherein the detecting means supplies the state of charge of the battery to a display portion which displays a remaining service time of the battery.

14. A method of detecting a state of charge of a battery, comprising:

(A) measuring a first output of the battery when connected to a first load and a second output of the battery when connected to a second load; and

(B) performing a predetermined computation on the basis of both the first output of the battery and the second output of the battery to detect the state of charge of the battery.

15. A method in accordance with claim 14 wherein said performing step includes supplying the state of charge of the battery to a display portion which displays the remaining service time of the battery.

16. A method of detecting a state of charge of a battery, comprising:

(A) measuring a first output of the battery when connected to a first load and a second output of the battery when connected to a second load; and

(B) performing a predetermined computation on the basis of both the first output of the battery and the second output of the battery to detect the state of charge of the battery, wherein the performing step corrects the state of charge of the battery on the basis of a reference data.

17. A method in accordance with claim 16 wherein said performing step includes supplying the state of charge of the battery to a display portion which displays the remaining service time of the battery.

18. A method of detecting a state of charge of a battery, comprising:

(A) measuring a first output of the battery when connected to a first load and a second output of the battery when connected to a second load;

(B) temperature compensating the first output of the battery and the second output of the battery on the basis of a temperature condition; and

(C) performing predetermined computation on the basis of both the first output of the battery and the second output of the battery to detect the state of charge of the battery, said first output of the battery and said second output of the battery being temperature-compensated by said temperature compensating step.

19. A method in accordance with claim 18 wherein said performing step includes supplying the state of charge of the battery to a display portion which displays the remaining service time of the battery.

20. A method of detecting a state of charge of a battery, comprising:

(A) measuring a first output of the battery when a system connected to the battery is in a first operation mode and a second output of the battery when the system connected to the battery is in a second operation mode, said first operation mode and said second operation mode having a different load;

(B) performing predetermined computation on the basis of both the first output of the battery and the second output of the battery to detect the state of charge of the battery; and

(C) compensating the state of charge of the battery when one of the first and second operation modes continues for a predetermined period on the basis of consumption of the battery in the operation mode.

21. A method in accordance with claim 20 wherein said performing step includes supplying the state of charge of the battery to a display portion which displays the remaining service time of the battery.