Well, it's considered good practice to first allow all the power in your laptop's battery to drain out (from use, without the laptop being connected to the power), and then plug in the power to recharge it fully. This ensures all the cells within the battery get discharged and recharged and none die before the other, therefore ensuring longevity for the battery.
However, it is a must to go by this process every single time?How often should I exhaust my laptop battery's power and re-charge, as a process?It is NOT a good idea to let the laptop's battery drain out, like many people say. It is too hard on the battery. What you need to do is to do at least 1 cycle per month (the equivalent of discharging it completely and recharging it completely, but it is better to do like 1/2 discharging, 1/2 charging, 1/2 discharging, 1/2 charging to do the cycle instead of draining it completely down).
I used to let my laptop's battery drain completely and now it only lasts an hour at best so it's not the way to go.