I have observed that the programs that require a large amount of RAM, graphics memory, processing power, for eg. video games, run slower and lag when the charging power is not plugged.
This happens even if the laptop is fully charged. And it is not just the case with old laptop, I have observed this in brand new laptops as well.
What is the reason for this? Are there any settings that I can change to prevent this because continuous charging can damage the battery?
Many operating systems will use more conservative performance settings when a portable computer is operating on battery power. Higher CPU (and GPU) processing frequencies mean more heat output and higher power consumption. Throttling these is meant to help extend the runtime on battery as well as control the laptop's rate of heat generation.
You should be able to override these power saving settings by using a pre-configured "High Performance" power profile or by configuring your own custom power settings for use while off utility power.
