1. Field of the Invention
The present invention relates to a battery pack, and more particularly, to a battery pack that is prevented from being shorted and that is capable of reducing idle power.
2. Description of the Related Art
Recently, compact and light electrical and electronic apparatuses such as mobile telephones, notebook computers, and camcorders have been actively developed and produced. Battery packs are built in the portable electrical and electronic apparatuses so that the portable electrical and electronic apparatuses can operate in a space where an additional power source is not provided. The battery packs recently adopt batteries that may be charged and discharged in consideration of economics. The batteries include a nickel-cadmium (Ni—Cd) battery, a nickel-hydrogen (Ni-MH) battery, a lithium (Li) battery, and a lithium ion (Li-ion) battery. In particular, since the operation voltage of the lithium secondary battery is three times higher than the operation voltages of the Ni—Cd battery and the Ni—H battery that are widely used as the contemporary power sources of the portable electronic apparatuses, and the energy density per unit weigh of the lithium ion secondary battery is high, the use of the lithium ion secondary battery rapidly increases.
In the lithium secondary battery, lithium based oxides are used as positive electrode active materials and carbon materials are used as negative electrode active materials. In general, the lithium ion secondary battery is divided into a liquid electrolyte battery and a polymer electrolyte battery in accordance with the kind of an electrolyte. The battery in which the liquid electrolyte is used is referred to as a lithium ion battery and the battery in which the polymer electrolyte is used is referred to as a lithium polymer battery. In addition, the lithium secondary battery is manufactured to have various shapes such as a cylinder type, a square type, and a pouch type.
A protection circuit part is attached to the lithium ion battery such that the lithium ion battery may be selectively charged and discharged, or that power is blocked to protect the lithium ion battery when the lithium ion battery is overcharged or when over-current flows. Therefore, the lithium ion battery is integrated with the protection circuit part to form a pack and is connected to a charger to perform charging or is connected to a portable electronic product that is a load to perform discharging.
At this time, the protection circuit part includes a positive terminal and a negative terminal connected to the charger or the load. When the positive and negative terminals are shorted by a clip or a conductor, the lithium ion battery deteriorates or causes the protection circuit part to abnormally operate.
In addition, the protection circuit part is integrated with the lithium ion battery to form the pack. Although the lithium ion battery is not connected to the charger or the load, the protection circuit part receives power from the lithium ion battery to protect the lithium ion battery so that the power of the lithium ion battery is continuously consumed.