how much power the laptop has. Most of the laptops today have the Sony batteries. Sony batteries were the ones recalled by Dell and the other laptop companies. I have a Sager that lets me use a second battery also. The laptop is a gaming computer with a 17' screen and can get 4 hours of battery life. That's great for a 17" screen and the battery wasn't a Sony so it wasn't recalled for catching on fire like the Sonys.