This ASUS replacement battery pack is a 6600mAh, 14.4, rechargeable, removable, Li-ion battery designed to work with ASUS UL50VS. The Hi-Quality battery meets or exceeds original manufacturer specifications for the ASUS UL50VS Laptop Battery in quality, durability, and performance. Li-ion batteries do not suffer from the memory effect. They generally last between 300-500 charge/discharge cycles. All laptop batteries are tested for 100% quality control assurance. This battery for ASUS UL50VS includes a one year warranty. We offer a 30 day money back guarantee and fast shipping on all of our products.