Battery voltage detection apparatus and detection method

• US 20010019269A1
• Filed: 01/18/2001
• Published: 09/06/2001
• Est. Priority Date: 01/18/2000
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Yudahira, Hirofumi
• Granted Patent: US 6,462,550 B2
• Time in Patent Office: Days
• US Class Current: 324/426
• CPC Class Codes: B60K 6/28 characterised by the electric energy storing means, e.g. batteries or capacitors
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
• CPC Class Codes: Y10S 903/903 having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/907 Electricity storage, e.g. battery, capacitor

Abstract

A voltage detection apparatus for detecting a voltage of at least one battery includes: capacitor means to which a voltage is applied from the at least one battery and in which an electric charge accumulates; adjustment means for adjusting potentials at both ends of the capacitor means such that a potential difference between a potential at one end of the capacitor means and a reference potential is less than a potential difference between a potential at one end of the at least one battery and the reference potential, and that a potential difference between a potential at another end of the capacitor means and the reference potential is less than a potential difference between a potential at another end of the at least one battery and the reference potential; and voltage detection means for detecting a voltage of the at least one battery based on a potential difference between the one end of the capacitor means and the other end of the capacitor means after the potentials of both ends of the capacitor means have been adjusted by the adjustment means.

Claims

1. A voltage detection apparatus for detecting a voltage of at least one battery, comprising:

capacitor means to which a voltage is applied from the at least one battery and in which an electric charge accumulates;

adjustment means for adjusting potentials at both ends of the capacitor means such that a potential difference between a potential at one end of the capacitor means and a reference potential is less than a potential difference between a potential at one end of the at least one battery and the reference potential, and that a potential difference between a potential at another end of the capacitor means and the reference potential is less than a potential difference between a potential at another end of the at least one battery and the reference potential; and

voltage detection means for detecting a voltage of the at least one battery based on a potential difference between the one end of the capacitor means and the other end of the capacitor means after the potentials of both ends of the capacitor means have been adjusted by the adjustment means.

2. A voltage detection apparatus according to

claim 1

, wherein the capacitor means comprises a plurality of capacitors in a series connection.

3. A voltage detection apparatus according to

claim 1

, wherein:

the capacitor means is electrically connected with the at least one battery via a first switching means;

the adjustment means comprises a second switching means for switching a state of the capacitor means so as to be electrically coupled or decoupled to or from a prescribed potential; and

the voltage detection means is electrically coupled to the capacitor means via a third switching means.

4. A voltage detection apparatus according to

claim 3

, wherein the capacitor means is electrically coupled to the prescribed potential via the second switching means and the potentials at both ends of the capacitor means are adjusted.

5. A voltage detection apparatus according to

claim 1

, wherein a potential difference between the one end of the at least one battery and the other end of the at least one battery is equal to the potential difference between the one end of the capacitor means and the other end of the capacitor means.

6. A voltage detection apparatus according to

claim 3

, wherein the capacitor means comprises a plurality of capacitors in a series connection and at least one node between the plurality of capacitors is coupled to the prescribed potential via the second switching means.

7. A voltage detection apparatus according to

claim 3

, further comprising a fourth switching means for switching a state of a first input terminal of the voltage detection means so as to be electrically coupled or decoupled to or from the reference potential.

8. A voltage detection apparatus according to

claim 7

, wherein the first input terminal is electrically coupled to the reference potential via the fourth switching means and a potential of the first input terminal is equal to the reference potential.

9. A voltage detection apparatus according to

claim 1

, further comprising conversion means for converting an analog signal from the voltage detection means to a digital signal.

10. A voltage detection apparatus according to

claim 1

, wherein the voltage detection means is a differential amplifier.

11. A method for detecting a voltage of at least one battery by means of the voltage detection apparatus according to

claim 3

, comprising the steps of:

electrically coupling the at least one battery to the capacitor means via the first switching means so as to allow an electric charge to accumulate in the capacitor means;

electrically isolating the at least one battery and the capacitor means from each other after the electric charge is accumulated in the capacitor means;

electrically coupling the capacitor means to the reference potential via the second switching means, thereby adjusting the potentials at both ends of the capacitor means;

electrically coupling the capacitor means to the voltage detection means via the third switching means; and

detecting the potential difference between the one end of the capacitor means and the other end of the capacitor means by means of the voltage detection means.

12. A method according to

claim 11

, wherein the voltage detection apparatus includes a fourth switching means for switching a state of a first input terminal of the voltage detection means so as to be electrically coupled or decoupled to or from the reference potential, the method further comprising the steps of:

electrically coupling the first input terminal to the reference potential via the fourth switching means; and

switching a state of the first input terminal so as not to be electrically coupled to the reference potential via the fourth switching means after the step of electrically coupling the capacitor means to the voltage detection means.

13. A method according to

claim 12

, wherein the step of adjusting the potentials at both ends of the capacitor means and the step of electrically coupling the first input terminal to the reference potential are performed simultaneously.