Battery pack

• US 6,437,540 B2
• Filed: 02/07/2001
• Issued: 08/20/2002
• Est. Priority Date: 02/07/2000
• Status: Expired due to Term

• Current Assignee: Envision AESC Energy Devices Ltd.
• Original Assignee: NEC Mobile Energy Corporation (NEC Corporation)
• Inventors: Sonobe, Satoshi
• Primary Examiner(s): Toatley, Gregory
• Assistant Examiner(s): LUK, LAWRENCE W
• Application Number:
  US09/777,860
• Publication Number:
  US 20010011883A1
• Time in Patent Office: 559 Days
• Field of Search: 320/134, 320/136, 320/132, 320/137, 320/116, 320/118, 320/119
• US Class Current: 320/134
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/00309 Overheat or overtemperature protection
• CPC Class Codes: H02J 7/0047 with monitoring or indicating devices or circuits
• CPC Class Codes: H02J 7/0049 Detection of fully charged condition
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current
• CPC Class Codes: H02J 7/007182 in response to battery voltage

Abstract

A battery pack, using a battery having one or more cells as a power source and for connecting power to an external host device, and including charging/discharging apparatus connected in series with the battery and for performing charging and discharging, current detecting apparatus for detecting charging and discharging current, voltage detecting apparatus for detecting voltage, temperature detecting means for detecting temperature, and a controller, whereby the controller is operated in such manner that it turns the state from at least one of charging state, discharging state, charging stop state, and discharging stop state to another state by controlling the charging/discharging apparatus based on the charging/discharging current, the voltage and the temperature as detected, and the state information is transmitted to the external host device when there is a request or at regular interval or when there is state transition, and state transition such as a charging/discharging state or a stop state of the battery pack controlled according to charging/discharging current, voltage, and temperature is controlled and information of state transition can be managed and controlled by the external host device.

Claims

1. A battery pack using a battery comprising one or more cells as a power source and for connecting power to an external host device, said battery pack comprising:

charging/discharging means connected in series to said battery and used for charging and discharging;

current detecting means for detecting the charging/discharging current;

voltage detecting means for detecting voltage; and

temperature detecting means for detecting temperature,

wherein at least charging state, discharging state, charging stop state and discharging stop state can be selected by controlling said charging/discharging means based on the charging/discharging current, the voltage, and the temperature as detected, and it is turned from one of these states to another state, and state transition information is transmitted to the external host device, and

wherein said charging/discharging means comprises a charging switch for charging said battery and a discharging switch for discharging said battery, said control means is operated in such manner that it is turned to the charging state or the discharging state when said charging switch and said discharging switch are both turned on and charging current or discharging current higher than a preset value is detected, it is turned to a charging stop state when the charging switch is turned off and the discharging switch is turned on, and it is turned to a discharge stop state when the charging switch is turned on and the discharging switch is turned off.

2. A battery pack according to claim 1, wherein said control means is operated in such manner that it is turned to system disconnection when it has been detected that connection with the external host device is disconnected, and the charging switch and the discharging switch are both turned off at the system disconnection, and this state is turned to a non-operation state.

3. A battery pack according to claim 1, wherein said charging/discharging means comprises a spare charging switch arranged in parallel to the charging switch and the discharging switch and used for charging with micro current, said control means is operated in such manner that the charging switch and the discharging switch are both turned off and only the spare charging switch is turned on when voltage is lower than a preset value, and it is turned to spare charging state.

4. A battery pack according to claim 3, wherein the control means is operated in such manner that the spare charging switch is turned off when the preset voltage value is not reached even when charging has been performed for a preset period of time with the preset amount of charging current in said spare charging state, and it is turned to a spare charging state.

5. A battery pack according to claim 3, wherein said control means is operated in such manner that, in the spare charging state, it is turned to the non-operation state under the condition that the cell voltage is higher than the preset value and system disconnection has been detected.

6. A battery pack according to claim 1, wherein said control means is operated in such manner that, when the voltage is compared with the preset value and pulse charging is performed, it is turned to a charging stop state when the average current during a preset period of time is lower than a preset value, and it is turned to a spare charging stop state based on full charging detection.

7. A battery pack according to claim 1, wherein said control means is operated in such manner that, when the voltage is compared with the preset value and pulse charging is performed, and when the charging temporary stop state where the charging switch is turned off and the discharging switch is turned on is longer than the preset period of time, it is turned to the charging stop state, and it is defined as a charging stop state based on full charging detection.

8. A battery pack according to claim 6 or 7, wherein the control means is operated in such manner that, in the spare charging stop state based on full charging detection, it is turned to the charging state under the condition that the charging ratio is lower than the preset value.

9. A battery pack according to claim 1, wherein said control means is operated in such manner that it is turned to charging stop state under the condition that the charging current is higher than the preset value, and this state is defined as a charging stop state based on abnormal current.

10. A battery pack according to claim 1, wherein said control means is operated in such manner that, in the charging state, it is turned to the charging stop state under the condition that the cell voltage is lower than the preset value even when the charging time is longer than the preset period of time, and this state is defined as a charging stop state based on abnormal charging time.

11. A battery pack according to any one of claim 6, 7, 9 or 10, wherein said control means is operated in such manner that, in the charging stop state based on the full charging detection, in the charge stop state based on abnormal current, and in the charging stop state based on abnormal charging time, it is turned to the discharging state under the condition that the discharging has been detected, and it is turned to the non-operation state under the condition that the system disconnection has been detected.

12. A battery pack according to claim 1, wherein the control means is operated in such manner that, in the charging state, it is turned to the charging stop state under the condition that the cell temperature is higher than the preset value, and this state is defined as a charging stop state based on temperature.

13. A battery pack according to claim 12, wherein the control means is operated in such manner that it is turned from the charging stop state based on the temperature to the charging state under the condition that the cell temperature is lower than the preset value.

14. A battery pack according to claim 1, wherein the control means is operated in such manner that, in the charging state, it is turned to the discharging stop state under the condition that the cell temperature is higher than the preset value, and this state is defined as a discharging stop state based on abnormal temperature.

15. A battery pack according to claim 1, wherein the control means is operated in such manner that, in the discharging state, it is turned to the discharging stop state under the condition that the discharging current is higher than the preset value, and this state is defined as a discharging stop state based on abnormal current.

16. A battery pack according to claim 1 wherein said control means is operated in such manner that said state transition information is transmitted to the external host device at least once when there is a request or at a regular interval or when there is state transition.

17. A battery pack according to claim 1, wherein the control means counts the time elapsed since it has been turned to the current state and this count value is transmitted to the external host device.