btw, I've a lenovo edge (i5-2410m, 15.6" 1366x768) and the battery can only last for 3 hrs in the first year. The problem was resolved in the second year ... coz the battery was dead (very low quality 短命種, right). I won't waste the $ to buy a new battery for this 5-yrs old device. Now it runs on AC all the time . It's basically a desktop pc!