Battery pack and electronic equipment having a discrimination function to determine battery pack type

1. A battery pack that is capable of being charged by and communicating with electronic equipment, the battery pack comprising:

a rechargeable battery;

a communication line to connect and communicate with the electric equipment;

a discrimination resistor electrically connected to said communication line; and

a controller having a discrimination section to output a discrimination signal to the electronic equipment,

wherein said communication line serves two discrimination functions to discriminate a type of the connected electronic equipment and/or battery pack, the two functions being (1) a first discrimination function by communicating with the electronic equipment via said communication line and digitally processing, and (2) a second discrimination function by applying a voltage to said discrimination resistor.

2. The battery pack as recited in claim 1 wherein said rechargeable battery is a lithium ion battery.

3. Electronic equipment that capable of charging a battery pack, the electronic equipment comprising:

a communication line to connect and communicate with the battery pack to serve two discrimination functions to determine battery pack type thereby; and

a control and power source circuit that charges a rechargeable battery housed in the battery pack,

wherein the discrimination functions include (1) a first discrimination function that is a digital discrimination function that determines battery pack type via communication with the battery pack, and (2) a second discrimination function that applies a voltage to a discrimination resistor in the battery pack to determine battery pack type, and

wherein said control and power source circuit charges a battery pack determined to be a specified product by either or both the first discrimination function and the second discrimination function, and does not charge a battery pack determined not to be the specified product.

4. The electronic equipment as recited in claim 3 wherein said control and power source circuit charges a battery pack, which is determined to be specified product by the first discrimination function, with a first charging voltage; and charges a battery pack, which is not determined to be specified product by the first discrimination function but is determined to be specified product by the second discrimination function, with a second charging voltage.

5. The electronic equipment as recited in claim 4 wherein said control and power source circuit sets the second charging voltage lower than the first charging voltage.

6. The electronic equipment as recited in claim 4 wherein said control and power source circuit charges a battery pack housing lithium ion rechargeable batteries.

7. The electronic equipment as recited in claim 4 wherein the first charging voltage for charging a battery pack with said control and power source circuit is 4.3V.

8. The electronic equipment as recited in claim 4 wherein the second charging voltage for charging a battery pack with said control and power source circuit is 4.2V.