Main Battery Pack (Celeron Processor Models) This is a 7 cell Nickel Metal Hydride rechargeable battery pack designed to work in select models of IBM ThinkPad A21e, A22e, 1800i series laptop and notebook computers. We are currently shipping the original IBM brand battery. This battery ships fully charged, tested and ready to work. This ENERGY+ item is built with the highest quality standards, safety features and has a 12 month warranty.