Netbooks are a smaller, lightweight version of a regular laptop, meaning they are easy to carry around with you. One of the main advances of netbook weight is the introduction of lithium-based batteries. Each lithium cell produces three time the voltage of a nickel-based cell, lasts longer and weighs about 40 percent less.
Lithium cells are slightly fatter than AA sized batteries, and for laptop batteries they are mainly rectagular, but generally about the same height. This means you can expect a netbook battery that contains 6 individual cells to be approximately twice the size of a netbook battery that contains 3 individual cells.
Although lithium cells are far lighter than nickel cells, the number of cells used to make your netbook battery pack has a direct bearing on weight. So if you want a netbook that's easy to move around, then the weight of a 3-cell battery is likely to be about 50 percent of a 6-cell battery's weight.
Endurance or capacity is measured in milliamp hours (mAh). Lithium cells are high capacity cells capable of producing between 1,200 and 2,400 mAh, depending on type. This means that your netbook can operate for longer between charges than other types of rechargeable batteries, and the less often you need to charge your notebook, the longer the battery will last before a replacement is required. The biggest difference between a 3-cell and 6-cell battery is that a 6-cell battery may last twice the amount of time. However, it is dependent on the amount of energy your netbook needs to operate. For example, a battery pack that produces 3,600 mAH will power an 800 mAh netbook for about four to five hours, whereas a 600 mAh netbook will last six hours.
Output in measured in volts, and a typical lithium battery cell produces 3.6 volts. This means a 3-cell netbook battery produces 10.8 volts, while a 6-cell battery produces 21.6 volts. The voltage your netbook needs to operate is based upon many factors, but an important one is the size of the processor inside your netbook. The larger the processor, the faster the machine computes information, but the greater the voltage. Having a 6-cell netbook battery inevitably means your netbook is more powerful, giving you greater speed and capability.