Electric vehicles and hybrid vehicles, which are operated by electric energy, are being developed to, e.g., reduce pollution. An electric vehicle may employ a battery pack as a main power source, and the battery pack may include a plurality of rechargeable battery cells therein. Further, the electric vehicles may make less noise, and do not generate exhaust gas. A hybrid vehicle may be a combination of an electric vehicle and an internal combustion engine vehicle, and may employ two or more power sources, e.g., a battery motor and an internal combustion engine.