A standard six-cell battery can last between four and five hours depending on the number of applications that are running on the computer. The life of a six-cell battery also can depend on the manufacturer of the battery and the computer that is using the battery.
Decreasing the brightness level of a computer's screen by even 10 percent can extend the life of a battery, especially on larger laptops. Many computers also come with battery-saving power settings that sacrifice processing power in exchange for using less of the battery's charge. Implementing any of these changes can result in increasing the life of a six-cell battery by more than an hour.