Should I leave my laptop plugged in all the time?

Modern laptops handle this far better than the folk wisdom assumes. Charging stops when the battery is full; it does not continue trickling energy into it. So leaving it connected does not overcharge anything.

The real consideration is that lithium batteries age faster when held at high charge, particularly when warm. A laptop permanently at full charge and running hot on a desk will lose capacity faster than one cycled moderately. The mechanism is chemical ageing over time rather than damage from the charger.

Manufacturers now address this directly. Most business laptops and an increasing number of consumer models include a charge limit setting, capping at around eighty percent when the machine is usually plugged in. If your laptop offers this, enabling it is the single most effective thing you can do for long-term battery health, and it is why a machine may sit at eighty percent and appear to refuse to charge further.

Heat remains the larger factor. A laptop plugged in and running demanding work continuously is warm, and that warmth affects the battery regardless of charge level. Ensuring good airflow matters more than charging habits.

The old advice about fully discharging periodically applies to a different battery chemistry and is actively unhelpful for lithium. Deep discharges are harder on these batteries than partial ones, and there is no memory effect to clear.

One practical exception: if you plan to store a laptop unused for months, leaving it at roughly half charge in a cool place is meaningfully better than storing it full or empty, since both extremes accelerate ageing during storage.