[dingdong-man]

i've been using my laptop for the last 3 years... its battery seems ok.but actually i never take out the battery even when i plugged it into AC power, because sometimes the power could be suddenly shut. so if i took it out, i could lose what i'm doing... but now i noticed the performace of my laptop is not as good as before... it only able to run the laptop up to 2.5 hours instead of 6 hours. i'm using Intel Centrino..

how is the best treatment for the battery??

[b1gapl]

The batteries life degrades over time. Also depending on how much you use it. I usually just buy a new battery, when it doesn't last as long anymore. But I keep the old battery, for backup just in case.

[Woden]

I'm assuming that it is a Lithium Ion battery and those start to lose capacity as soon as they are made. The older the battery the less charge it will hold. Here is a small excerpt from a Wikipedia article on it...

At a 100% charge level, a typical Li-ion laptop battery that is full most of the time at 25 degrees Celsius or 77 degrees Fahrenheit will irreversibly lose approximately 20% capacity per year. However, a battery stored inside a poorly ventilated laptop may be subject to a prolonged exposure to much higher temperatures than 25 °C, which will significantly shorten its life. The capacity loss begins from the time the battery was manufactured, and occurs even when the battery is unused. Different storage temperatures produce different loss results: 6% loss at 0 °C(32 °F), 20% at 25 °C(77 °F), and 35% at 40 °C(104 °F). When stored at 40% charge level, these figures are reduced to 2%, 4%, 15% at 0, 25 and 40 degrees Celsius respectively.

Lithium-ion battery - Wikipedia, the free encyclopedia