Laptop batteries have a tricky thing on them called memory. Its purpose is to give you a good idea of how much life you have remaining while you are working. In other words, when you hover your cursor over your laptop battery icon in the bottom-right corner, it gives you a time amount indicating how much longer you can continue to work on battery power. Once the time remaining falls to a certain point, the laptop will go into standby or hibernate mode in order to help prevent you from losing your work. While this memory feature of laptop batteries is very useful in most situations, it also presents a problem for many people who do not know how to properly care for their battery.
The battery is the primary source of power for a laptop, not the power cord. This means that if the battery is plugged in, the computer is going to draw power from it rather than from the power cord. When you have a fully charged battery and you also have the laptop plugged into the wall, your laptop draws just a very small amount of power from the battery which is immediately replaced by the power cord. In effect, imagine a refrigerator filled with half-gallons of milk. Now, imagine someone removing one half-gallon of milk and then immediately replacing it without ever using the other half-gallons. If this process is continued for a long enough period of time, the rest of the milk will spoil.
This is the simplest way I can explain how harmful it is to your battery to leave it plugged in constantly. Many people have the habit of leaving their power cords plugged into their laptops for extended periods of time without ever unplugging them. This is the worst thing you can possibly do to your battery, aside from throwing it into a river, which you shouldn’t do either.
If you plan to leave your power cord plugged in for an extended period of time, remove your battery. Most batteries can easily be removed with one or two latches on the underside of the laptop. Consult your laptop manual or Google.com if you cannot find the latches to release the battery.
By the way, an extended period of time does not mean 30 minutes or a couple of hours. If your laptop battery is showing 100%, there is no cause to panic as you scramble to remove the battery. This also should not prevent you from wanting to charge your battery overnight. When I say, “Do not leave your battery plugged up for extended periods of time,” I am talking about days, not hours. In other words, don’t leave your laptop plugged into the wall while it is fully charged for days on end.
If you do not want to remove your battery, you can try this: Once the battery is fully charged, remove the power adapter. Wait until the battery is showing between 5-10% power remaining, then plug it back in until it is fully charged. Rinse and repeat.
You would be shocked how long your battery will last if you follow this simple tip. My wife’s laptop is a little over a year old, and it may have lost 5-10 minutes in charge since it was brand new.
Store Manager and Lead Technician