This brand new Lenovo ThinkPad T420s, T420si replacement laptop battery features lithium-ion cells. 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 laptop battery replacement is 100% compatible with the original battery specifications and is individually tested and backed by a 1 year warranty.

You can expect about 2 hours to 2-1/2 hours of run time with this computer battery when new, depending on your energy use. If you are looking for even longer battery run times, check out our extended run battery for your Lenovo laptop.

Laptop Battery Express only deals with brand new premium computer batteries. We never carry recycled or used batteries. We only use the highest quality cells inside the battery pack so you will have a long service life (300-500 recharge cycles). We do not use cheaper battery cells which can wear out in a little as 6 months. Our inventory turns rapidly and you will always receive a freshly manufactured battery.