About battery of a raptop PC

I've got a new raptop PC.
And I wonder how I should treat the PC in terms of a battery.

When I leave the lab, I usually leave my raptop PC power on.
I wonder whether this action damage the PC and its battery.

According to some informations on the Web, the action is not good thing for the PC because the action keep HDD spinning and current of electricity flowing on battery.
Especially, damages to battery are serious.
continual current of electricity washes out the battery.

So I think that I had better use a suspend function.
But, Does suspend function need passing of currency on battery? :-(
I don't have any idea.