2차 또는 충전식 배터리라고도 하는 축전지는 재충전을 위해 전류가 통과해야 하는 배터리 유형입니다.  그들은 전기 자동차, 휴대용 전자 장치 및 재생 가능 에너지원용 에너지 저장 시스템과 같은 많은 응용 분야를 가지고 있습니다.
The commonest types of storage batteries are lead-acid, lithium-ion and nickel-cadmium batteries.  Lead-acid is the oldest and most used type; typically found in cars and other vehicles.  These ones aren’t too expensive but they have some disadvantages: their lifespan is short while regular maintenance is necessary.

On the other hand lithium-ion batteries require more money to buy but they last longer than lead acid batteries do, charge faster and contain more energy per kilogram or liter.  Smartphones, laptops and electric vehicles commonly use these ones.