Second battery control circuit

• US 6,925,400 B2
• Filed: 02/10/2004
• Issued: 08/02/2005
• Est. Priority Date: 03/16/1999
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Iwaizono, Yoshinori
• Primary Examiner(s): WACHSMAN, HAL D
• Application Number:
  US10/708,114
• Publication Number:
  US 20040167741A1
• Time in Patent Office: 539 Days
• Field of Search: 702 63- 65, 702/57, 702/99, 702/130, 702/132, 702/133, 702/136, 702/182, 702/183, 702/188, 320/152, 320/162, 320/113, 320/107, 320151-154, 320/137, 320/134, 320/128, 320/130, 320/150, 429/61, 429/62, 429/56, 429/57, 429/59, 429/90, 429/92, 324/426, 324/429, 324/431, 324/434, 340/455, 340/449, 340/657, 340/660, 340/636.1, 340/636.13, 340/636.15, 340/636.17, 340/636.18, 340/636.2, 374/137, 374/141, 374/142, 374/163, 374/183, 700/286, 700291-293, 700295-297, 700/299
• US Class Current: 702/63
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/007194 of the battery

Abstract

According to the present invention, there is provided a secondary battery control circuit which can perform a reliable charge/discharge control without activating Positive Temperature Coefficient element. The secondary battery control circuit includes a temperature detection section for detecting a temperature of the secondary battery and a system logic for controlling charging/discharging of the secondary battery based on the temperature detected by the temperature detection section. The system logic interrupts the charging of the secondary battery in a case where the temperature detected by the temperature detection section is out of a predetermined first temperature range, and interrupts the discharging of the secondary battery in a case where the temperature detected by the temperature detection section is out of a predetermined second temperature range.

Claims

1. A secondary battery control circuit comprising:

a voltage detection section for detecting a voltage of a secondary battery;

a temperature detection section for detecting a temperature of the secondary battery; and

a control section for controlling charging/discharging of the secondary battery based on a voltage detected by the voltage detection section and a temperature detected by the temperature detection section, wherein

in a case where the voltage detected by the voltage detection section is equal to or greater than a predetermined first voltage value, and the temperature detected by the temperature detection section is equal to or greater than a predetermined temperature, the control section discharges the secondary battery until the voltage of the secondary battery reaches a predetermined second voltage value.

2. A secondary battery control circuit according to claim 1, wherein the predetermined first voltage value and the predetermined second voltage value are detected by a single circuit having a hysteresis.

3. A secondary battery control circuit according to claim 1, wherein either the predetermined first voltage value or the predetermined second voltage value is equal to an overcharge releasing voltage value.

4. A secondary battery control circuit according to claim 1, wherein a discharge canceling condition for the secondary battery includes a temperature condition for the secondary battery.

5. A secondary battery control circuit according to claim 1, wherein the secondary battery control circuit is formed on a single semiconductor chip.

6. A secondary battery control circuit according to claim 5, wherein the single semiconductor chip is enclosed in a sealing section of the secondary battery.