Patent Number: 7,613,577

Title: Onboard battery monitoring apparatus and method for correcting offset value of current sensor thereof

Abstract: An onboard battery monitoring apparatus for monitoring charging and discharge currents of an onboard battery 40 using a current sensor 43 includes an ignition switch 49, a main line current interrupting unit 41 for interrupting a current of a main line A which constitutes a monitoring target to be monitored by the current sensor, a detecting unit 51 for detecting an output of the current sensor 43 when the ignition switch 49 is off and the main line current interrupting unit 41 is interrupting the current, and an offset value correcting unit 51 for correcting an offset value of the current sensor 43 using a value detected by the detecting unit 51. Since an output of the current sensor 43 resulting when a current to be measured by the current sensor 43 is 0 ampere is detected as an offset value, an offset value can be obtained in which a change in characteristics attributed to the tolerance and/or aging of the current sensor 43 is reflected, thereby making it possible to accurately correct the offset value of the current sensor 43.

Inventors: Yamaji; Shigeo (Toyota, JP), Asakura; Toshiyuki (Toyota, JP)

Assignee: Yazaki Corporation

International Classification: G01R 31/36 (20060101)

Expiration Date: 1/03/02017