I suggest to try to never let it get above approximately 75% charged.
I've owned two laptops. The first was always fully charged, and the battery needed replacing within a year. The second laptop is going on 4 years on the original battery, and has very rarely been charged above 75%, and has no significant loss of battery life. Limiting the charge was probably easier for me than it would be for you, though, as my laptop had a feature that would allow you to force it to stop charging at a 75% charge (or 40%, if you were so inclined to limit it that low). Apparently it worked.
It's just the way Lithium-Ion batteries work. Ideal charge to store them at is 40%, although this severely limits the amount of charge you will have when you actually need to use the laptop on battery alone. The higher a charge they are kept at, the sooner they will need replacing. Same with temperature. Prolonged exposure to higher temperatures (such as those that result from gaming on a laptop) will result in a need to replace the battery sooner.