Skip to content
logo The magazine for digital lifestyle and entertainment
Caution

Almost everyone does it! This error destroys your laptop battery

Laptops should not be permanently connected to the power supply. But not because of possible overcharging.
Laptops should not be permanently connected to a power supply. But the reason is not because of possible overcharging. Photo: Getty Images

September 17, 2024, 8:20 am | Read time: 4 minutes

Many users are increasingly turning to laptops in the office and home office. Connected to the monitor, they act like a classic PC but offer the advantage of also being able to be used on the move. However, it is precisely this hybrid use option that allows many people to make a mistake when using a laptop.

Share article

Unlike a classic PC, a laptop has an integrated battery. In newer, mostly flat devices, this is permanently installed and, therefore, cannot be easily replaced. If the battery capacity decreases, the laptop can only be used to a limited extent. However, many people make a mistake that has a negative impact on battery capacity.

Typical batteries in laptops

Laptops are generally equipped with one of the following three types of battery:

  • Lithium-ion
  • Lithium-polymer
  • Nickel-metal hydride

Nickel-metal hydride batteries are comparatively rare; manufacturers use lithium-ion or lithium-polymer batteries much more frequently. They are characterized by their high energy density, meaning they can store a lot of energy despite their compact design. Depending on use and storage, lithium batteries last for several years. It is therefore important to look after the batteries in the laptops accordingly.

In principle, lithium polymer batteries are somewhat more sensitive than lithium-ion batteries, especially when it comes to overcharging and temperature. Conversely, they can be made thinner and more flexible, offering new application possibilities. Lithium-polymer batteries are a further development of ion technology whereby the structure of both battery types is very similar. However, they differ in one important respect.

Lithium-ion batteries consist of a negative electrode (anode) and a positive electrode (cathode), between which so-called lithium ions and electrons move in opposite directions through a liquid electrolyte. If they move from the negative to the positive pole, the battery is discharged. Conversely, the battery is charged. The structure of lithium polymer batteries is almost identical. However, lithium ions and electrons do not move through a liquid electrolyte but through a solid or gel-like polymer-based electrolyte. The more solid basic structure enables the construction of very thin layers and, therefore, a very variable design of the lithium polymer batteries.

Why continuous charging damages the laptop battery

It is particularly problematic for older laptop models if they are constantly connected to the power supply. They then run the risk of being overcharged, which weakens the battery long-term and minimizes its performance. The batteries of newer laptops usually recognize when they are connected to the power supply and react accordingly to prevent this overcharging. Manufacturers often also provide software-based protective measures. Nevertheless, it is not advisable to leave the devices plugged into the power socket all the time.

Neither lithium-ion nor polymer batteries have a memory effect. Without software support, they do not remember the charge level of the battery and, therefore, always charge it to the maximum. However, once a 100 percent charge is reached, the charging process is interrupted. The current then no longer flows into the battery but supplies the laptop directly. This minimizes the risk of overcharging enormously. If a laptop is permanently connected to the power supply, the danger lies elsewhere.

Charging the battery or supplying it directly with electricity always generates heat. Especially when the battery is charged, and the electrons have nowhere to go. However, the lifespan of a battery is significantly reduced at certain temperatures. Ranges of -20 °C or +50 °C are usually declared as critical. If a battery is repeatedly exposed to cold or heat, its service life slowly decreases.

If a laptop is permanently connected to the power supply, it is not the excessive flow of energy that is the problem but the long-term damage caused by constant exposure to heat. After a certain time, the battery is no longer as powerful and is, therefore, less able to retain energy. The result: it discharges more quickly.

More on the topic

How to protect the laptop battery

What some users don’t know: If a laptop is connected to a monitor via Thunderbolt, it draws power via the cable. This also results in a certain amount of heat being generated permanently. This can be prevented with appropriate ventilation. Ideally, the laptop should be placed on a stand through which air can circulate on the underside. However, you should avoid placing the device on a cushion or other soft surface for long periods. It can also be helpful to close energy-hungry applications regularly so they do not continue running in the background.

This article is a machine translation of the original German version of TECHBOOK and has been reviewed for accuracy and quality by a native speaker. For feedback, please contact us at info@techbook.de.

Topics Battery Evergreener
Your data privacy when using the share function
To share this article or other content via social networks, we need your consent for this .
You have successfully withdrawn your consent to the processing of personal data through tracking and advertising when using this website. You can now consent to data processing again or object to legitimate interests.