This is a brand new replacement battery. The superior South Korean cells inside the battery cartridge will provide longer run times between charges as well as a longer service life than cheaper batteries. 

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 Laptop. The battery is individually tested before shipment and backed by 30 day complete satisfaction guarantee and a 11 months warranty.