The battery for the Alienware M17x series laptop comes in two different shapes. In order to ensure that you receive the correct battery you should take your battery out and compare it to the picture above.
This Alienware M17x battery features the highest quality lithium-ion cells and battery components. Li-ion battery technology provides longer run times with less weight. In addition, Li-ion batteries are not subject to the memory effect common with older battery technology. This M17X battery replacement is 100% compatible with the original battery specifications and is individually tested and backed by a 1 year warranty.