Well i’ve used a laptop for about two and a half years right now and i have finally decided how i’m gonna use the laptop battery from the next time. Initially i thought working with the charger connected to the supply when ever possible would take the strain off the battery and in turn the battery would charge up first and my laptop would be taking charge directly from the power supply. I did that because i read in my laptop manufacturers guide that the laptop would stop charging the battery and would start taking supply directly. Well i was wrong. All through that could be true. I live in a place where the power goes off frequently. And due to those small charge-discharge sequence that happens during power cuts my battery has lost its capacity.
Now i feel its better to use the laptop as much as possible with the battery. Charge it fully. Use it fully. Charge it again(fully). Just like you would do on your cell phones. I hope you do know that its always advised to charge your cell phones fully and drain it off fully(below 10%) before you charge it again. This would increase your battery life.
Although if you live in a place where power cuts are not the issue you could try the way i did. Although when a power cut does occur. Discharge the battery completely before charging it again when the power comes back.