This is a brand new Asus A32- U53 9 Cell Extended Run replacement battery. This battery ships fully tested and ready to go. Inside the Asus U53 battery are South Korea's best Lithium-ion rechargeable battery cells. The superior battery cells will provide longer run times between charges as well as a longer service life than cheaper batteries. In addition, Li-ion batteries are not subject to the memory effect common with older battery technology. This means you can recharge your laptop any time without diminishing your battery capacity. This laptop battery replacement is typically superior to the original battery and is 100% compatible with your Asus U53 notebook computer. The battery is individually tested before shipment and backed by 30 day complete satisfaction guarantee and a 2 Year warranty.