Leaving Laptop Plugged in Overnight: Bad?

Here’s whether it’s bad to leave your laptop plugged in overnight:


A single overnight charge will not harm a modern battery. 

But, leaving the laptop plugged in perpetually can shorten the battery’s lifespan. 

If you’ve ever heard that leaving the laptop plugged in can overcharge the battery, that’s not true for lithium-ion devices, but it was true for older battery types.

If you want to learn all about whether it’s bad to leave your laptop plugged in overnight, then you’re in the right place.

Here’s what you need to know!

Leaving Laptop Plugged in Overnight: Bad? (Or Even Longer)

Why Shouldn’t You Leave Your Laptop Plugged In Overnight?

Laptops come in many designs and functions, so the specifics of your computer might not be identical to what is normal for most laptops. 

That said, the vast majority of modern laptop batteries are made from lithium-ion or comparable lithium compounds, and they all work pretty much the same way.

These batteries are preferred for their longevity and low maintenance requirements. 

Most laptop batteries are rated for hundreds of recharges, but that brings this conversation to the most important point. 

Every time a battery is charged, it takes a little bit of chemical damage in the process. 

Eventually, that chemical damage adds up, and the battery won’t last as long as it used to.

This chemical damage is perfectly safe for you as a user. 

What it really means is that no battery will last forever. 

Over time, it will hold less charge than it used to, and eventually, it won’t be able to hold any charge at all.

Since recharging a battery inevitably kills it, how does that factor in when you leave your laptop charging overnight? 

Well, that has to do with charge cycles. 

Your lithium-ion battery is well-designed. 

When it is low, it will accept charge from the plug until it is full. 

Once full, the battery won’t accept charge anymore. 

If you’ve ever heard that leaving the laptop plugged in can overcharge the battery, that’s not true for lithium-ion devices (but it was true for older battery types).

So, when you leave the laptop charging through the night, it will ultimately fill the battery, and then the battery will stop charging. That’s why it’s perfectly safe to do this.

There’s a huge catch to all of this. As long as the battery is plugged into the computer, it will slowly release very small amounts of electricity to the computer. 

This is called a trickle charge, and as the trickle charge drains a few fractions of a percent of your laptop’s battery capacity, the battery will once again accept juice from the charger. 

This will happen on and off again countless times throughout the night after the battery gets full for the first time.

The thing to remember is that this is happening on a very small scale. 

The trickle charge and recharge of a single night will have no discernable impact on your battery’s health. 

It will take many dozens, if not hundreds, of overnight charges to impact the battery.

The bigger concern is when you leave the battery plugged in indefinitely. 

When the battery doesn’t get a break from the trickle charge throughout the day and night, you’ll see those detrimental effects sooner than when you only charge overnight.

What Is the Best Way to Charge a Laptop? (Do This)

It might feel like a cursed if you do, cursed if you don’t situation right now, and that’s kind of true. 

No matter what you do, your battery will lose health over time. 

If you’re trying to maximize how long the battery lasts, there are a few ideas and best practices that can help.

Killing a Battery Quickly

The first thing to know is that some things hurt the battery a lot more than other things. 

For instance, draining the battery all the way to zero and leaving it there is the fastest way to ruin it. 

You’re much better off plugging the laptop in as soon as you get any low battery warnings. 

Experts disagree on the magic number, but it’s a good idea to charge your battery when it gets down to about 20 percent. 

If you jump in before that number, you’re erring on the safe side.

Another thing that can annihilate your battery is extreme temperatures. 

When the battery gets too hot, it sustains damage, and it won’t charge as well as it used to. 

You can definitely kill a battery with heat. 

Naturally, you don’t want to leave it in your car in the middle of July, but there’s a more common source of heat.

The laptop itself can get pretty hot, especially if you’re working it pretty hard. Here’s a general rule. 

If the laptop is ever uncomfortably hot to the touch, it needs a break. 

That’s hot enough to start harming the battery, and any hotter can be the end. 

If you turn it off and let it rest, it will cool back down and be fine. 

In this case, it’s best to unplug the laptop while it cools. The charger adds a little bit of heat to the equation.

Cold temperatures can be just as bad. So don’t put your laptop into the freezer to cool it down.

Most batteries are rated to operate normally as long as it’s above freezing. 

If you want to be extra safe, treat your laptop like you treat yourself. 

If you need a jacket, it’s probably too cold to store the laptop for a long period of time. 

If you’re sure it’s below freezing, definitely get the computer to a warmer place.

Best Practices for Maximizing Battery Life

You know what to avoid. 

What can you do right to extend your battery life? 

A few actions go a long way. 

The first is to only use as needed. 

More importantly, only charge the battery as needed. 

Ultimately, charging is what kills the battery, so if you’re not planning to use the laptop, you don’t need to recharge it right away (unless it’s completely drained). 

This reduces charging cycles on average, and it will give you a little more mileage out of your battery.

Another thing you can do is plan around the charge capacity of the battery. 

If it’s already full, don’t charge it overnight. That only adds to the trickle charge battery and contributes to a shorter lifespan. 

Instead, let it charge overnight when it’s below half. You get the most value out of your charge in that scenario.

Another thing you can try is removing the battery. 

Keep in mind that not all batteries are removable. Especially with ultra-thin laptops, they might be enclosed or soldered. 

If the battery is accessible, then you can remove it to prevent it from experiencing stress.

Obviously, this only works for laptops that sit on a desk all day and don’t live a mobile life. 

If that’s the case, you can keep your battery stored and pop it back in if you ever do need to move the laptop.

Keep in mind that the battery will lose charge over time, even when it is unplugged. 

A healthy lithium-ion battery will lose somewhere around 10 percent of its charge every two months. 

This number can vary heavily from device to device, but it’s a ballpark figure to help you plan. 

You still don’t want to let the battery sit on empty, so every few months, recharge it. Using the battery this way can extend its life by years.

How to Remove a Laptop Battery?

Remember, not all batteries are removable. When they are, the process is simple. 

They will typically have one or two sliding lock mechanisms. 

The slides are labeled with lock and unlock icons, usually resembling a padlock. 

To remove the battery, slide all of the locks to the open position. It should pop free.

Line it up so that any plastic tabs or slides won’t get stuck, and slide it into place to put the battery back in. 

It should click when it is fully seated, and the slide-locks will engage themselves. 

If you can’t find the mechanisms listed, double-check with your manufacturer. 

They should have an online owner’s manual that will show you the specifics of battery removal for your model.

Can You Leave a Battery Plugged in All the Time?

It might feel like we’ve covered this, but it’s possible to dig a little deeper. 

We’ve established that there is a trickle charge when a full battery is plugged in. 

We’ve also covered that the trickle charge causes the battery to pull electricity from the charger and microscopically lower its lifespan.

That should mean that leaving it plugged in all the time is a bad idea, right? 

That’s mostly true, but you will still find some manufacturers that recommend always leaving the laptop plugged in when possible.

What’s the catch?

This stems from the fact that the trickle charge will not kill the battery as quickly as stressful use. 

If the battery drains very quickly, you’re going to put a lot of charge and depletion stress on the device. That can cause it to undergo chemical damage a lot faster than normal. 

Meanwhile, trickle charge from leaving it plugged in is never going to kill the battery quickly.

Some manufacturers go with this recommendation as a bit of a hedged bet. 

An uninformed user is more likely to stress their battery by leaving it unplugged than by leaving it perpetually plugged in because they haven’t covered the intricacies of how laptop use affects battery life. 

You now know the difference between these recommendations, so you can make an informed decision.

The right way to charge a laptop mostly depends on the case-by-case specifics, and that’s the real answer.


  • Theresa McDonough

    Tech entrepreneur and founder of Tech Medic, who has become a prominent advocate for the Right to Repair movement. She has testified before the US Federal Trade Commission and been featured on CBS Sunday Morning, helping influence change within the tech industry.

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