No, it's fine. Modern laptops regulate power once the battery is full; the bigger risk is running hot for months on end.
People worry about overcharging a laptop because early lithium batteries really could degrade from constant full charge. Laptop battery management has moved well past that.
The setting that actually matters isn't whether you unplug the charger, it's whether the laptop is trapped somewhere hot while it works.
Once a laptop battery reaches 100%, the charger stops feeding the battery and powers the laptop directly from the wall instead. The battery sits idle rather than being continuously topped off.
Many laptops, including Dell, Lenovo, HP, and MacBooks with Apple's Battery Health Management, offer a mode that caps charging around 80% when the laptop stays plugged in most of the time. This reduces time spent at full charge, which is gentler on the cell long term.
A laptop battery kept plugged in most of the time and used moderately typically still holds around 80% of its original capacity after roughly 3-4 years, similar to one cycled daily, as long as heat is controlled.
If you're storing the laptop for weeks, charge it to roughly 50% first. Lithium-ion batteries age slower in long-term storage at partial charge than at 100% or 0%.
Leaving a laptop plugged in isn't the mistake it's made out to be. Watch the heat, use a battery care mode if your laptop has one, and don't worry about the cable.
No. Most modern laptops have non-removable batteries anyway, and removable ones don't need this either since the charging circuit already prevents overcharging.
No. Normal plugged-in use is expected, standard behavior that manufacturers design for and cover under warranty terms.
Keeping a lithium-ion battery roughly between 20% and 80% most of the time slows aging, which is why battery care modes cap charging near 80%.
Not immediately, but sustained heat above about 95°F/35°C over months does accelerate capacity loss more than normal use.