Battery charging device

• US 6,362,600 B2
• Filed: 01/18/2001
• Issued: 03/26/2002
• Est. Priority Date: 01/24/2000
• Status: Expired due to Term

• Current Assignee: Makita Corporation
• Original Assignee: Makita Corporation
• Inventors: Sakakibara, Kazuyuki
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): LUK, LAWRENCE W
• Application Number:
  US09/766,881
• Publication Number:
  US 20010011884A1
• Time in Patent Office: 432 Days
• Field of Search: 320/150, 320/144, 320/137, 320/128, 320/127, 320/119, 320/116, 320/151, 320/152
• US Class Current: 320/150
• CPC Class Codes: H02J 7/0014 Circuits for equalisation of charge between batteries
• CPC Class Codes: H02J 7/00309 Overheat or overtemperature protection
• CPC Class Codes: H02J 7/007194 of the battery

Abstract

In a battery charging device 10 capable of detecting abnormalities in cells comprising batteries through a simple arrangement and terminating charge accordingly, cell temperature information Ta and cell temperature information Tb in charging operation within respective blocks A and B are detected through temperature sensors TM1, TM2 and a temperature detecting portion 38 incorporated in a battery package 50, the cell temperature information Ta of block A and cell temperature information Tb of block B are compared through a comparing/determining portion 35 wherein upon determining that temperature difference information Tdf is exceeding reference information for comparison Tref, instructions for terminating charging operations are sent from a control portion 36 to a charge current controlling portion 34 assuming that abnormalities have occurred in the cells comprising the block A or block B during charging operations. With this arrangement, it is possible to detect a block including abnormal cells whose temperature does not rise or fall within a specified range together with remaining cells within the same block and to detect inconveniences of charge circuits or the like that performs charge upon division into blocks, and to terminate charging operations for the battery package 50.

Claims

1. A battery charging device for charging batteries comprised of a plurality of cells, the battery charging device comprising:

a temperature detecting portion for detecting cell temperatures during charging operations within groups of cells for each of groups of cells in which a plurality of cells has been divided into two or more,

a comparing portion for comparing the cell temperature of one group of cells with that of another group of cells,

a determining portion for determining whether a temperature difference between the cell temperatures as compared by the comparing portion is exceeding a specified value or not, and

a control portion for terminating charge when it is determined by the determining portion that the temperature difference between cell temperatures is exceeding the specified value.

2. A battery charging device for performing charge of batteries comprised of a plurality of cells upon dividing the cells into two or more groups of cells, the battery charging device comprising:

a temperature detecting portion for detecting cell temperatures during charging operations within groups of cells for each of groups of cells,

a comparing portion for comparing the cell temperature of one group of cells with that of another group of cells,

a determining portion for determining whether a temperature difference between the cell temperatures as compared by the comparing portion is exceeding a specified value or not, and

a control portion for terminating charge when it is determined by the determining portion that the temperature difference between cell temperatures is exceeding the specified value.