A laptop battery will recharge only a certain number of times and each full to empty comes back a little less.
Heat also wears a battery.
Plugging and unplugging the power port wears that out.
If you are usually at a station, keep it plugged in. I guess, wow I never knew it was bad to do that. So yeah keep it plugged in all the time. Actually keeping your laptop plugged in at all times will harm your battery. Higher charge percentage = higher voltage and less discharge cycles, which may sound good but actually these are necesarry for battery health.
You should unplug when the percentage is over 80, replug when it gets down to the 20s-30s, even if you're using the computer all day. The act of plugging/unplugging harms nothing. Remaining plugged and at 100% at all times can kill your battery up to 3 times faster because it is getting constant power and heat. The battery only recharges so many times - limited number of recharges. Keeping it plugged in all/most of the time is not the same as recharging it, therefore prolonging the life of the battery. Do NOT keep it plugged in all the time! Batteries are not made for endless incoming power in fact they are made to avoid it. To say it makes tthem healthy is nonsense. Ask urself what kind of battery would need to be plugged in always. It defeats the whole purpouse of the battery