H/T Mental Floss.
Now you know the rest of the story.
A weak battery can make a perfectly good laptop unusable. This is a common problem for laptop owners, and there are plenty of tips out there for how to prevent it. If you want to extend your computer battery’s life as long as possible, just be careful about which advice you follow. The old idea that leaving a laptop plugged in for too long will hurt it is simply not the case.
According to Windows Central, this myth comes from the idea that laptops can be overcharged. Modern laptops use one of two battery types: lithium-polymer or lithium-ion. Both devices are designed to stop charging the moment they hit 100 percent power. Instead of passing through the full battery first, the power from the charging cord will be diverted directly into the computer. This means that keeping a fully charged laptop plugged in all day won’t damage the power unit.
As Protect Your Gadget points out, this does come with a caveat. A laptop battery is healthiest when it maintains a charge of roughly 70 to 80 percent. If the charge is kept too low or too high on a consistent basis, your battery won’t last as long. Of course, keeping your charge hovering around 75 percent throughout the workday isn’t always practical. Instead of obsessing over the specific number, try to unplug your device periodically once it’s fully charged and plug it back in once it dips below 50 percent power.
Though the technology has improved significantly in recent years, the death of your laptop battery is still inevitable. The moment you power up your new computer for the first time, the lithium inside starts to degrade. The best way to extend its longevity is to make sure your laptop isn’t consuming more power than necessary. Do this by closing any unused apps that are running in the background and adjusting the battery settings on your device. Heat is another major factor when it comes to battery life. Too much of it can damage your lithium battery, so make sure the bottom of your computer is always properly ventilated.