Battery pack

• US 7,298,113 B2
• Filed: 10/18/2004
• Issued: 11/20/2007
• Est. Priority Date: 10/27/2003
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Orikasa, Hironobu
• Primary Examiner(s): Vu; Bao Q.
• Assistant Examiner(s): Zhang; Jue
• Application Number:
  US10/967,559
• Publication Number:
  US 20050127871A1
• Time in Patent Office: 1,128 Days
• Field of Search: 320/110, 320/112, 320/113, 320/103, 320/138, 320/140
• US Class Current: 320/112
• CPC Class Codes: H01M 10/42 Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells H01M10/60 takes precedence
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H01M 6/5033 used as charging means for another battery
• CPC Class Codes: H02J 2207/40 adapted for charging from various sources, e.g. AC, DC or multivoltage
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence
• CPC Class Codes: H02J 7/342 The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging with circuits for polarity protection H02J7/0034
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A detecting switch which is turned on/off in accordance with whether or not primary batteries have been attached to a primary battery holder is provided. In a normal state where no primary battery is attached, terminals (a, c) of a charge change-over switch are connected by a detection signal of the detecting switch, so that a voltage supplied from an external charger is inputted to a DC/DC converter. A secondary battery is charged by a predetermined value output of the DC/DC converter. When the primary batteries are attached, the detecting switch is turned on and terminals (b, c) of the charge change-over switch are connected, so that an output voltage of the primary batteries is inputted to the DC/DC converter. The secondary battery is charged by the predetermined value output of the DC/DC converter. Even when there is no charger, the secondary battery can be charged by the primary batteries and charging power sources are automatically switched.

Claims

1. A battery pack having a secondary battery, comprising:

a holding unit for detachably holding a primary battery;

a switch for switching a voltage of said primary battery and a voltage at an external terminal;

a voltage converter to which either said primary battery voltage or said external terminal voltage selected by said switch is inputted and which supplies a stabilized output voltage to a positive polarity side of said secondary battery;

a protecting unit that performs overcharge, overdischarge and overcurrent protection;

a control unit for controlling said switch so as to select said external terminal voltage in a normal state and, when said primary battery is attached, select said primary battery voltage; and

a light emitting device that is turned on only in the state where said secondary battery is charged by either said primary battery voltage or by said external terminal voltage,

wherein,

said control unit is a switch which is provided for said holding unit and detects that said primary battery has been attached, and

a light emitting device light-on switch is turned on when an output terminal of an AND gate is equal to “

1” and

a detection signal of said detecting switch is inputted to one input terminal of the AND gate and a charge control signal from said protecting circuit is supplied to the other input terminal of the AND gate.

2. A pack according to claim 1, wherein when an input voltage is lower than a set voltage value, said voltage converter increases the voltage and, when said input voltage is higher than said set voltage value, said voltage converter decreases the voltage.

3. A pack according to claim 1, wherein said voltage converter is a DC/DC converter.

4. A pack according to claim 1, wherein said control means is a monitor for detecting that a value of said primary battery voltage is larger than a set value.

5. A pack according to claim 1, wherein said control means is a monitor for detecting that a value of said external terminal voltage is larger than a set value.

6. A pack according to claim 1, wherein said control means is a monitor for comparing a level of said primary battery voltage with that of said external terminal voltage and detecting the voltage of the higher level.