Improve the performance and operating time of you laptop while away from home by buying the right battery. One that will hold a better charge and not drain away when you find there is no access to an ac outlet.

To identify the battery type, you can remove your current battery and review the label, then find what that is interchangeable. Better yet, have you laptop make and model of your machine ready. Since there is some possiblity however remote that the battery you are already running could be incorrect.
The make and model is the best starting point to go buy.

There are three main types of laptop batteries;

Nickel Cadmium - and older type of battery which is not empowered as much as the new cells. If you have a nicad, you should monitor the charging time and not allow overcharging. Some of the batteries, familair to power tool owners as well, also have irregularities when it comes to putting them on the charger too soon.

Nickel Metal Hydride - the next evolving member, holds a heartier charge and it si more amiable to getting juiced.

Lithium ion - is the latest in batteries. They offer major drops in weight, making you laptop easier to tote around. As you maty have guessed, you can expect to pay quite a bit more for lithuim.

The above are all nice facts. However, be aware that many laptops are designed for use with a specific type of battery.

Besides the kind and brand of battery you decide to buy, other things like ambient room temperature, and the load placed on the battery will help determine how it performs and lasts for you.