Circuit for detecting remaining battery capacity

• US 20070188146A1
• Filed: 02/12/2007
• Published: 08/16/2007
• Est. Priority Date: 02/13/2006
• Status: Active Grant

• Current Assignee: Mitsumi Electric Co., Ltd. (MinebeaMitsumi Inc.)
• Original Assignee: Mitsumi Electric Co., Ltd. (MinebeaMitsumi Inc.)
• Inventors: Ikeuchi, Akira, Nakano, Itsuki
• Granted Patent: US 8,076,904 B2
• Time in Patent Office: Days
• US Class Current: 320/132
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]

Abstract

A disclosed circuit for detecting remaining battery capacity includes: a current detection unit detecting a charge and discharge current of a battery; a remaining capacity measurement unit measuring remaining capacity of the battery by integrating the charge and discharge current at first time intervals when the charge and discharge current detected in the current detection unit is not more than a predetermined value and at second time intervals shorter than the first time intervals when the charge and discharge current exceeds the predetermined value; and an interrupt signal generation unit generating an interrupt signal when the charge and discharge current exceeds a reference value and instructing the remaining capacity measurement unit to measure remaining capacity of the battery.

Claims

1. A circuit for detecting remaining battery capacity, comprising:

a current detection unit detecting a charge and discharge current of a battery;

a remaining capacity measurement unit measuring remaining capacity of the battery by integrating the charge and discharge current at first time intervals when the charge and discharge current detected in the current detection unit is not more than a predetermined value and at second time intervals shorter than the first time intervals when the charge and discharge current exceeds the predetermined value; and

an interrupt signal generation unit generating an interrupt signal when the charge and discharge current exceeds a reference value and instructing the remaining capacity measurement unit to measure remaining capacity of the battery.

2. The circuit for detecting remaining battery capacity according to claim 1, wherein

the current detection unit detects a voltage between both ends of a resistance where the charge and discharge current passes through, and

the interrupt signal generation unit generates the interrupt signal when the voltage between both ends of the resistance where the charge and discharge current passes through exceeds a first reference value and when the voltage between both ends of the resistance where the charge and discharge current passes through is less than a second reference value lower than the first reference value.

3. The circuit for detecting remaining battery capacity according to claim 2, wherein

the interrupt signal generation unit includes a window comparator.