I got one friend, his laptop is newer than mine. However, the battery is already working bad. The battery will lost the power quickly. But my laptop’s battery still can work about 1 hour plus.
And I just read about lithium-ion battery (which is used in laptop, PDA, and handphone). The following is the quotation from http://electronics.howstuffworks.com/lithium-ion-battery.htm/printable.
Lithium ion chemistry prefers partial discharge to deep discharge, so it’s best to avoid taking the battery all the way down to zero. Since lithium-ion chemistry does not have a “memory”, you do not harm the battery pack with a partial discharge. If the voltage of a lithium-ion cell drops below a certain level, it’s ruined.
Lithium-ion batteries age. They only last two to three years, even if they are sitting on a shelf unused. So do not “avoid using” the battery with the thought that the battery pack will last five years. It won’t. Also, if you are buying a new battery pack, you want to make sure it really is new. If it has been sitting on a shelf in the store for a year, it won’t last very long. Manufacturing dates are important.
So, just try to save the battery life yourself.