Some computer manufacturers provide support apps. Asus does and it recommends for battery life, to charge to 60% and no higher and provides a program that will do that.
If you think about it, everytime you use your computer it will keep the battery charged at that percentage. Now if you have your battery constantly at 100% everytime you use the computer the battery will lose a bit of power and then have to recharge to 100%. At least with 60% it does not have to do that as many times.
This is also why phones shouldn't be charged overnight, because once they are fully charged, they'll start losing a little charge and then recharge to that 100%, and lose a little charge and so on, wearing out the battery faster.
