This Lenovo Thinkpad laptop battery replacement features Li-ion chemistry within its cells. Li-ion battery technology provides longer run times with less weight. In addition, This laptop battery replacement is 100% compatible with the original battery specifications. This is a long life battery with 8 cells. Estimated run time on this battery is over 7 hours using optimal battery management settings on your laptop. This extended life battery will extend the overall size of your laptop to the rear of your laptop and will not seat in the ThinkPad X6 UltraBase. This battery is rated for 14.4 volts and 4800 mAh capacity.This is more than double the battery life of the original 4 cell battery rated at 2000 mAh capacity. Each laptop battery is individually tested and backed by a 1 year warranty. If you prefer to keep the original compact shape of your laptop, the battery # LEN-11 will not protrude out the rear of your laptop.