Should You Leave Your Laptop Plugged in All the Time?

Turns out, the answer isn’t entirely straightforward. So let’s take a look.

Know Your Laptop Battery

There are two main types of batteries used in laptops: lithium-ion and lithium-polymer. Although they are different technologies, they function in broadly the same way, generating power through the movement of electrons. This constant flow is also needed to help keep the battery healthy.

For both types of batteries, the following statements are true (at least as far as modern laptops are concerned):

• A battery cannot be overcharged. There’s no danger of overcharging a battery if you leave it plugged in all the time, even 24/7. As soon as it hits 100 percent, it will cease charging and won’t start again until the voltage falls below a certain level.
• Fully discharging a battery will damage it. Allowing the battery to become completely empty for an extended period can put it into a deep discharge state. This can be fatal—you might never be able to charge it again. 

So, based on this, do we conclude that you should leave your laptop plugged in all the time? Not quite.

Things That Damage Lithium Batteries

The truth about lithium-based batteries is that they are inherently unstable. They begin to lose capacity from the moment they are produced, and numerous factors hasten their decline. These include:

• Charge/discharge cycles. Every battery has a finite number of times it can be charged and discharged.
• Voltage level. The higher the charge level (measured in volts per cell), the shorter the battery’s life.
• High temperature, over 30 degrees celsius. This can cause irreparable damage.

The last two are the ones that we’re most concerned with here. A comprehensive study by Battery University highlights how voltage levels and high temperatures will shorten the life of a battery in isolation and even more when they combine.

Charge or Voltage Level

Lithium-ion batteries charge to 4.20 volts per cell, which amounts to 100 percent of their capacity. At this level, the battery will have a lifespan of 300-500 discharge cycles.

It all comes down to the power management setup in the laptop. Some may reduce the power when a battery isn’t present, just as some do when the battery level gets low. This could leave you with subpar performance.

If you do choose to remove the battery, ensure that you store it properly. This usually means being charged between 40 percent and 80 percent and kept at room temperature.

Should You Keep Your Laptop Plugged In?

Does leaving your laptop plugged in ruin the battery? Yes, it does. But then so does charging it every day.

Curiously, the industry as a whole doesn’t seem to have settled on a single answer for the question about whether to use your laptop on AC or battery power.

We’ve seen that Acer recommends removing the battery when you aren’t using it. Asus says you should drain the battery to at least 50 percent every two weeks. But Dell says there’s no problem leaving the laptop plugged in at all times.

Apple’s advice is no longer on its website, but you can still read it online. The company recommends against leaving a laptop plugged in all the time. Instead, it suggests:

“An ideal user would be a commuter who uses her notebook on the train, then plugs it in at the office to charge. This keeps the battery juices flowing…”

Is It Bad to Keep Your Laptop Plugged In?

Leaving your laptop plugged in will not cause short-term damage, but if you only ever use it on AC power, you’ll almost certainly find that after a year, the battery’s capacity has been significantly reduced. Similarly, if you only ever use it on battery power, you’ll get through the battery’s discharge cycles quicker.

So, the best solution is something of a compromise between the two: use it on battery power some days, and keep it plugged in on others. And whatever you do, you’ll want to make sure it doesn’t get too hot.

Source: makeuseof