The new generation laptops use Li-ion batteries for the power. I have observed that these batteries go defunct within a short time (~1 to 2 years) based on the usage.
As per my usage characteristics, I was assuming that the laptop remains hooked to the docking station most of the time and the discharge cycle from the battery is very low. Very rarely the battery gets discharged completely. And thus this affects the battery life.
On reading a few articles, it seems that Li-ion batteries does not suffer from the "memory" effect. But rather the heat generated from the laptop is the one that reduces the life span of the battery. More over these kind of batteries has the aging effect.
If you use keep your laptop hooked to docking station most of the time and have a reliable UPS backup, then remove and store the battery in a cool place to get most out of it.