The useful lifespan of the battery is adversely affected by the following usage patterns:
Using the computer on constant AC power.
Not discharging and recharging the battery to its extremes, as described above.
Frequent use; the more you use the battery, the faster it will reach the end of its effective life. An embedded battery has a life span of more than 1,000 charge/discharge cycles.
Optimizing battery life
Use AC power whenever possible, reserving battery for mobile use.
Excessive recharging decreases the battery life.