Troubles with the wood

Briefly. I have on the laptop this problem. Videokart NVIDIA 610M. Device Manager sees it so. Wood office site set. But in games when the laptop is charging gives 15 to 20 fps and when off the charger on the cooler and increases the fps to 30 40. It works exactly the opposite as it should be Windu changed 100 times settings changed elektropitanie nothing helps. Help me out...