How to Choose a Laptop Power Supply
Categories: Education
The laptop power adapter is arguably the most sensitive component of the entire mobile computer. Often forgotten, haphazardly coiled, and carelessly thrown into a bag, the power adapter is particularly vulnerable to damage. For this reason, this accessory is replaced quite frequently. The most common reasons for replacement include cable breakage, damaged plug, or overheating. If you're also planning to buy a new power adapter, it's worth familiarizing yourself with our article, where we'll focus on the most important things to consider.
Laptop Power Adapter from the Manufacturer
Often, the simplest answer to the question of which power adapter is suitable for your laptop is to purchase a spare power adapter directly from the device manufacturer. The advantage of an original charger is the confidence that the laptop and power adapter will work seamlessly. To order a replacement power adapter, you typically need the product number (sometimes abbreviated as P/N) or the exact laptop model name.
Usually, this information can be found on a sticker on the bottom of the laptop. If the manufacturer of your model can't assist you, you always have the option to use replica power adapters. They are available in various options on the internet or in electronics stores. Additionally, spare power adapters from third-party manufacturers often come at a lower cost than original replacements.
How to Choose a Power Supply?
When selecting a power supply for your laptop, it's essential to consider the following information:
- Input voltage
- Output voltage
- Output current
- Output power
- Type of connector
These details can usually be found on the sticker attached to the original power supply or on the laptop itself. In case you've misplaced your power supply, you may also find this information on the bottom of your laptop.
Voltage: Precision is Key
The voltage of the new power supply must match exactly with that of your laptop. The voltage is measured in volts (V). Even slight deviations of a few percent should be avoided to prevent potential overvoltage issues.
Amperage: Current Strength
The current intensity, measured in amperes (A), is crucial as it determines the power delivered by the power supply. The current should be at least equal to the laptop's requirements.
Higher current values are not harmful, but they won't necessarily make your laptop run faster or charge the battery more quickly. Your laptop will simply not utilize the full potential of the power supply. On the other hand, if you opt for a power supply with lower ratings than what your laptop needs, you may experience insufficient power to operate all the components or charge the battery properly.
Polarity: pay attention to plus and minus
Laptop power supplies use so-called "hollow plugs". These are plugs with a round contact and a hole in the middle. With these connectors, you should pay attention to the polarity. The polarity indicates whether the positive pole is inside and the negative pole is outside, or vice versa. Polarity information (usually in the form of a small graphic) can be found under the output on an old power supply or on the bottom of a laptop.
The vast majority of laptop power supplies use the internal positive pole as this reduces the risk of a short circuit. However, you should check this.
Voltage and current determine wattage
The wattage of the power supply is also important. It is given in watts and is the result of multiplying the voltage and current. If you don't want to do the math yourself, you can usually find information about the required performance of your laptop in the user manual.
Values slightly above the required power are usually harmless. However, if the performance of the new power supply is much higher than the notebook needs, the power supply may generate excessive heat and the notebook will use unnecessary amounts of electricity.
Which plug does your new laptop power adapter need?
You can usually find the dimensions of your laptop's power adapter connector in your laptop's manual. They are listed there by outer dimension and inner dimension (in mm). If you can't find any information in your laptop's user manual, you can take the measurements manually. But you have to be very precise to get accurate measurements.
The connectors in laptop power supplies are not subject to any standards. This does not make it easy to find the right replacement power supply. Also keep in mind that some laptop manufacturers use, for example, an extra pin in the middle of their connectors.
Are there any universal power supplies?
The answer to this question is yes. There are a lot of universal power supplies on the market. Their undoubted advantage is the fact that you can easily get the voltage and current with a knob or slider, and manufacturers additionally include several interchangeable plugs in different sizes. Thanks to this solution, you can charge several different laptops (and often other devices) using a single power supply. However, when using such a power supply, be especially careful not to accidentally set the wrong parameters and thus damage not only the battery but also the entire laptop.
Lost or damaged the power supply? No problem.
Losing a power supply is annoying, but it doesn't have to be a problem. What may seem complicated at first glance is actually not that difficult. With the right replacement power supply, you can still use your laptop freely.
The safest solution is to use replacement power supplies directly from the manufacturer of your laptop. However, if you pay special attention to the voltage, amperage, polarity, and dimensions of the plug, you can also use a replacement power supply successfully. Third-party charging cables are often a cost-effective and equally reliable alternative.