Battery protection device, battery protection system using the same, and battery protection method

• US 20050242780A1
• Filed: 01/28/2005
• Published: 11/03/2005
• Est. Priority Date: 04/28/2004
• Status: Active Grant

• Current Assignee: Mitsumi Electric Co., Ltd. (MinebeaMitsumi Inc.)
• Original Assignee: Mitsumi Electric Co., Ltd. (MinebeaMitsumi Inc.)
• Inventors: Abe, Shuhei, Sakuma, Katsuya, Ooshita, Kazuhiro, Terada, Yukihiro
• Granted Patent: US 7,397,221 B2
• Time in Patent Office: Days
• US Class Current: 320/134
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A battery protection device protects a battery from an abnormal state. The battery protection device includes a detector that detects an abnormality of the battery and outputs an abnormality detection signal when the abnormality is detected. A current is input to an input terminal from outside. A voltage converter converts the current input to the input terminal to voltage and outputs the voltage. A combiner combines the abnormality detection signal with the voltage and outputs a combined signal. A current converter converts the combined signal to a current. An output terminal outputs the current.

Claims

1. A battery protection device for protecting a battery from an abnormal state,

the battery protection device comprising:

a detector that detects an abnormality of the battery and outputs an abnormality detection signal when the abnormality is detected;

an input terminal to which a current is input from outside;

a voltage converter that converts the current input to the input terminal to voltage and outputs the voltage;

a combiner that combines the abnormality detection signal with the voltage and outputs a combined signal;

a current converter that converts the combined signal to a current; and

an output terminal that outputs the current.

2. The battery protection device as claimed in claim 1, wherein the battery protection device is formed by a semiconductor integrated circuit chip.

3. A battery protection system for protecting a plurality of batteries connected in series from an abnormal state,

the battery protection system comprising:

a switching element connected to the batteries in series;

a plurality of battery protection devices which devices are provided for the batteries in a corresponding manner, detect an abnormal state of the corresponding batteries, and output an abnormality detection signal; and

a drive circuit that drives the switching element in accordance with the abnormality detection signal,

each of the battery protection devices including;

a detector that detects an abnormality of a corresponding one of the batteries and outputs the abnormality detection signal when the abnormality is detected;

an input terminal to which a current is input from outside;

a voltage converter that converts the current input to the input terminal to voltage and outputs the voltage;

a combiner that combines the abnormality detection signal with the voltage and outputs a combined signal;

a current converter that converts the combined signal to a current; and

an output terminal that outputs the current,

wherein the battery protection devices are connected to each other such that the output terminal of one of the battery protection devices is connected to the input terminal of a subsequent one of the battery protection devices, and

the output terminal of one of the battery protection devices of a last stage is connected to the drive circuit.

4. The battery protection system as claimed in claim 3, wherein each of the battery protection devices is formed by a semiconductor integrated circuit chip.

5. A battery protection method for protecting a plurality of batteries connected in series from an abnormal state,

the battery protection method comprising the steps of:

providing battery protection circuits for the batteries in a corresponding manner, each of the battery protection circuits including;

a detector that detects an abnormality of a corresponding one of the batteries and outputs an abnormality detection signal when the abnormality is detected;

an input terminal to which a current is input from outside;

a voltage converter that converts the current input to the input terminal to voltage and outputs the voltage;

a combiner that combines the abnormality detection signal with the voltage and outputs a combined signal;

a current converter that converts the combined signal to a current; and

an output terminal that outputs the current;

connecting the battery protection devices to each other such that the output terminal of one of the battery protection devices is connected to the input terminal of a sequential one of the battery protection devices; and

controlling a switching element connected to the batteries in series in accordance with the current output from the output terminal of one of the battery protection devices of a last stage, thereby controlling the batteries.