Should I Leave My Laptop Plugged In All The Time?
It won’t make all that much difference. What will shorten battery life is temperature: If it gets hot, it will shorten the battery life. Best thing to do, if you are able, is to remove the battery while you’re at home and keep it somewhere cool.
If it’s a Li-ion battery, then they don’t like to be completely discharged, so make sure you charge them regularly. Wikipedia:
Lithium-ion batteries should not be frequently discharged fully and recharged (“deep-cycled”), but this may be necessary after about every 30th recharge to recalibrate any electronic charge monitor (e.g. a battery meter). This allows the monitoring electronics to more accurately estimate battery charge. This has nothing to do with the memory effect.
What about the “Remove the battery!” camp? It turns out that while removing the battery can be beneficial, the situations in which it is beneficial are fairly limited.
The answer is: YES and NO, it depends on the situation.
Having a battery fully charged and the laptop plugged in is not harmful, because as soon as the charge level reaches 100% the battery stops receiving charging energy and this energy is bypassed directly to the power supply system of the laptop.
However there’s a disadvantage in keeping the battery in its socket when the laptop is plugged in, but only if it’s currently suffering from excessive heating caused by the laptop hardware.
In a normal usage, if the laptop doesn’t get to hot (CPU and Hard Disk around 40ºC) the battery should remain in the laptop socket;
In an intensive usage which leads to a large amount of heat produced (i.e. Games) the battery should be removed from the socket in order to prevent unwanted heating.
The heat, among the fact that it has 100% of charge, is the great enemy of the lithium battery and not the plug, as many might think so.
The best plan of attack then, is to monitor your hardware to ensure you’re not overheating your battery and be concious of the limitations of the type of battery in your device–for the majority of users, a Lithium-Ion battery.