leave my laptop plugged in to power supply always?

Charlotte_Orange wrote:

Is it better for the battery life of my laptop to be plugged in to power supply when in use or is it better to plug in only when battery needs a charge?

If you are near the mains leave it plugged in, if you need portability run on the battery—in this way you extend the working life of the battery. You can expect a cycle count of 1000.

Determine battery cycle count for Mac notebooks

https://support.apple.com/en-us/HT201585

About battery health management in Mac notebooks— introduced with macOS10.15.5

https://support.apple.com/en-us/HT211094

Its ok to leave it plugged in as apple has a smart chip which stops the current once your mac reaches 100 and waits for it to discharge a little and then charge again. However, its always better to let the battery do the charge and discharge cycles to maintain a healthy battery life.

Hope this helps.

You can leave your computer plugged in when convenient to do so. Neither your computer nor battery will be damaged by leaving it plugged in. Leaving it plugged in reduces the rate of accumulation of battery cycles.