Battery pack

• US 4,818,928 A
• Filed: 10/01/1987
• Issued: 04/04/1989
• Est. Priority Date: 10/01/1987
• Status: Expired due to Term

• Current Assignee: Gillette Company (The Procter & Gamble Company)
• Original Assignee: Duracell Incorporated (Berkshire Hathaway Incorporated)
• Inventors: Schosser, John F.
• Primary Examiner(s): Hickey, R. J.
• Application Number:
  US07/103,622
• Time in Patent Office: 551 Days
• Field of Search: 320/2-6, 320/15-18, 320/13, 320/7, 429/99
• US Class Current: 320/112
• CPC Class Codes: H01M 50/213 adapted for cells having curved cross-section, e.g. round or elliptic H01M50/209, H01M50/216 take precedence
• CPC Class Codes: H01M 50/253 adapted for specific cells, e.g. electrochemical cells operating at high temperature
• CPC Class Codes: H01M 50/269 Mechanical means for varying the arrangement of batteries or cells for different uses, e.g. for changing the number of batteries or for switching between series and parallel wiring methods or arrangements for servicing or maintenance H01M6/50, H01M10/42
• CPC Class Codes: H01M 50/271 Lids or covers for the racks or secondary casings
• CPC Class Codes: H01M 50/296 characterised by terminals of battery packs terminals of batteries H01M50/543
• CPC Class Codes: H01M 6/50 Methods or arrangements for servicing or maintenance, e.g. for maintaining operating temperature constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 6/5011 for several cells simultaneously or successively
• CPC Class Codes: H02J 7/0024 Parallel/serial switching of connection of batteries to charge or load circuit

Abstract

This invention pertains to portable battery-pack power supplies for use in devices which must be operated between an upper voltage and a lower voltage limit. The battery pack is comprised of a main power supply and a reserve power supply. The reserve power supply is switched into series connection with the main power supply when said main power supply is discharged to the lower voltage limit. Means are provided for ensuring that only the initial power supply is switched into the circuit after fresh cells are installed in the battery pack.

Claims

1. A battery-pack power supply which operates between upper and lower voltage limits, said battery-pack comprising a plurality of electrochemical cells connected to provide a main power supply having a voltage which does not exceed a predetermined upper voltage limit and a reserve power supply having a voltage which does not exceed the difference between the upper and lower voltage limits;

switch means in said battery pack for interconnecting in a first position only the main power supply into an electronic circuit to be powered by said battery-pack and, alternately for connecting in a second position both the reserve power supply the circuit and the main power supply into the electronic circuit to be powered by the battery-pack; and

means for ensuring that the switch means is in the first position when cells are installed in the battery-pack whereby only the main power supply becomes interconnected upon installation.

2. A battery-pack power supply for operating a device, wherein said device operates between upper and lower voltage limits, said battery-pack comprising a housing having a removable cover;

first and second external terminals mounted on said housing;

a main power supply contained within the housing and comprising one or more electrochemical cells having a combined voltage which does not exceed the upper voltage limit wherein said main power supply has first and second terminals, and said first terminal being connected to the first external terminal of the battery-pack;

a reserve power supply contained within the housing and comprising one or more electrochemical cells having a combined voltage which does not exceed the difference between the upper and lower voltage limits, said reserve power supply having first terminal and second terminals;

a switch having a first position and a second position, said switch being operatively connected to the main power supply, the reserve power supply, and the second external terminal of the battery-pack, whereby in the first position of the switch, the second terminal of the main power supply is connected to the second external terminal of the battery-pack, and in the second position of the switch the first terminal of the reserve power supply is connected to the second terminal of the main power supply and the second terminal of the reserve power supply is connected to the second external terminal of the battery-pack; and

means for preventing installation of the cells in the battery-pack unless the switch is in the first position.

3. The battery-pack of claim 2 wherein the cells are primary cells.

4. The battery-pack of claim 2 wherein the cells are alkaline manganese cells.

5. The battery-pack of claim 4 wherein said switch is a single pole, double throw switch.

6. In combination a battery-pack power supply and a camcorder which is adapted to operate between an upper voltage limit of about 12 volts and a lower voltage limit of about 9 volts, said battery-pack comprising a housing;

a cover for the housing;

first and second external terminals mounted on said housing;

a main power supply contained within the housing comprising eight AA alkaline-manganese cells having a combined voltage of about 12 volts;

a reserve power supply contained within the housing comprising two AA alkaline-manganese cells having a combined voltage of three volts; and

switching means having first position and second positions, said switching means being operatively associated with the main power supply, the reserve power supply, and the external terminals of the battery-pack to provide a first position in which the switching means connects the main power supply to the external terminals of the battery-pack, and a second position in which both the main and reserve power supplies are connected in series to the external terminals of the battery-pack.

7. The combination of claim 6 and further including a member attached to the cover which engages with the switch such that the switch must be in the first position while the cover is removed orreplaced thus ensuring that only the main power supply is initially connected to the external terminals of the battery-pack when fresh cells are installed.