This is a brand new Asus R558U battery. This Asus R558U battery uses the best Lithium-ion battery cells and components. The superior battery cells will provide longer run times between charges as well as a longer service life than cheaper batteries. This Asus R558U battery is compatible with the R558U, R558UQ and R558UF models as well as the C21N1509 battery part number.

This Asus R558U battery is 100% compatible with your Asus VivoBook and each battery is individually tested before shipment and backed by 30 day complete satisfaction guarantee and a 2 Year warranty.

This Asus R558U battery is rated 7.6 volts and 38 Whr and will normally last 5 hours on a full charge. You can get longer battery life by dimming your screen and closing unused programs.