I went online looking for and upgraded replacement for the factory or "stock" battery if you will. The factory battery was only a six cell unit that charged at about a medium rate. It would only last two hours maybe two and a half at best. Under heavy load barely over one and a half hours. So i went in search of a faster charging longer lasting replacement that would not break the house budget and use all the grocery money. I came across this site by using GOOGLE and was at first intrigued by the warranty length of two years as opposed to everyone else's one year warranty.This is a nine cell battery, a three cell upgrade, made with lithium ion technology. It is a fast charge with a longer heavy use life. It lasts roughly up to two and a half to three times longer than the factory and is much cheaper. So the savings can purchase you a second long life battery to carry for extra use. I give it two thumbs up.