The do's and don'ts of laptop charging

Ken Colburn
Special to The Republic
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Keeping any relatively current laptop plugged in and charged at 100% for extended periods of time shouldn’t be a problem, but it’s best not to do so for a number of reasons.

Q: Does it harm my laptop battery if I just keep it plugged into my charger all the time?

A: Battery life continues to be one of the biggest complaints of laptop users, so understanding what you can do to help prolong the life is important.

Technically speaking, keeping any relatively current laptop plugged in and charged at 100% for extended periods of time shouldn’t be a problem, but it’s best not to do so for a number of reasons.

Battery Management System (BMS)

Today’s laptop batteries have sophisticated battery management systems that monitor your State Of Charge (SOC) and drop the voltage down as it gets closer to a full charge.

Once the SOC is at 100, it is designed to switch to the AC connection directly and only provide a trickle charge to the battery should it need it.

We should be able to rely on the BMS to keep things charging properly, but a number of things can impact the BMS which could lead to overcharging the battery when it’s plugged in all of the time.

Overcharging can lead to overheating, which can lead to catastrophic chemical reactions inside the battery.

In severe cases, BMS failure can lead to "thermal run-away," which can result in hazardous fires or exploding batteries.

We’ve all heard the stories of dangers with devices such as hoverboards, smartphones and laptops powered by lithium-ion batteries, which are generally caused by thermal run-away. This is also what leads to laptop recalls from time to time.

Keeping your battery charged between 40% and 80% has been shown to extend battery life, and if you aren’t going to use your laptop for a while, turn it off and unplug it from the charger.

Preventative maintenance:How to keep your computer running smoothly

Improper charger

If you use a third-party charger instead of the one provided by the manufacturer, this mismatch can cause issues, especially once the battery’s SOC goes above 80%. This is when an adjustment to the charging voltage should occur and when it doesn’t, bad things can happen.

Charging temperatures

Charging your laptop when it’s above or below the recommended operating temperature can cause issues or degrade the battery, so make sure your laptop is at room temperature before you plug it in to charge it.

If you charge your laptop near a window that exposes it to direct sunlight, move it to a location away from any direct sunlight.

Make sure the small exhaust vents — typically in the back of most laptops — aren’t being blocked to prevent heat buildup as charging the battery generates heat.

Signs of a damaged battery

If you notice that the bottom of your laptop becomes uncomfortably hot when you are charging or using the laptop, it may be an indication that you have a damaged battery.

Other symptoms we often see with batteries that have clearly overheated and bulged are touchpads and keyboards that are intermittently responsive or when you can feel that they are no longer fully flat.

Anecdotally, most laptops that we service that exhibit these physical symptoms from a bulging battery were confirmed to be plugged in all the time to a charger.

Proactively replacing your battery when it’s showing signs of a problem will allow you to start fresh with a new approach as to how, when and where you charge your laptop and avoid any potential catastrophes.

Ken Colburn is founder and CEO of Data Doctors Computer Services, Ask any tech question at or on Twitter @TheDataDoc.

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