Smartphone et PC en toute sécurité ! Comment choisir un chargeur USB | Comment trouver le modèle optimal.

Smartphones, tablets, wireless headphones, laptops, and more – the number of devices charged via USB is really increasing.
Along with that, the types of USB chargers are diversifying incredibly.
With a lot of specialized terms like output wattage and port types, many people may be wondering, “Which one should I choose?”

Choosing the wrong charger can not only result in slow charging but also prevent you from taking full advantage of your device’s performance, and in the worst case, it can lead to safety issues such as device failure or overheating.
Thinking “As long as it charges, anything will do” and choosing randomly is actually a very dangerous action.

This article will resolve your doubts and anxieties about choosing a USB charger and explain in an easy-to-understand manner how to find the best one for your devices with confidence.
Please read to the end and make your digital life more comfortable and safe.

Basic knowledge to find the optimal USB charger

Choosing a USB charger is extremely important for your digital life.

Why is choosing a charger important now? What risks are involved in making the wrong choice? And what is the current situation with smartphones? We will explain the basics in an easy-to-understand manner.

Avoiding risks due to incorrect selection

If you choose the wrong USB charger, several risks may occur.
First, the most immediate risk is that charging will take a long time.
If you use a charger with an output (wattage) lower than what your device requires, it may take hours to fully charge, preventing you from using your device immediately.

More seriously, there is a risk of device failure or overheating.
Using poor-quality products or products that are incompatible with your device can cause unstable voltage or current, which can overload the device, accelerate battery degradation, or damage internal circuits.

Especially, products that do not meet the Japanese Electrical Appliance and Materials Safety Law standards, meaning they do not have a PSE mark, are not guaranteed to be safe.
“You get what you pay for” is true, but it can also lead to damage to your valuable devices. Therefore, it is very important to have the awareness of “choosing a good product.”

The arrival of the smartphone era without chargers

In the past, when you bought a smartphone, a charger (AC adapter) and cable were always included in the box.
However, recently, Apple has stopped including chargers with the iPhone 12 series and later, citing environmental considerations.

This means that even if you buy a new smartphone, you need to prepare a charger separately.
Those of you who have been using the included charger without thinking about it need to understand how to choose one and find a charger that suits your smartphone.

There are many high-performance and convenient products other than genuine ones, so learn the correct knowledge and choose a charger with confidence.

Step 1 in choosing a USB charger: Confirming your devices

The most basic step in choosing a USB charger is to accurately know what we want to charge.
Identifying all the devices you want to charge is the first and most important step in finding the optimal charger.

It is important to confirm in advance what connection terminals your devices have and what fast charging standards they support.
By doing so, you can avoid regretting your charger choice.

Listing the devices to be charged

Listing the devices to be charged is an action to understand all the charging needs of your devices.
This is very useful in determining the “type” and “number” of chargers you need.

List all possible devices that may be charged via USB, including smartphones, tablets, laptops, wireless headphones, smartwatches, and portable game consoles.

By specifically listing the charging devices, you can clearly imagine the type and number of chargers needed.

4 factors that determine charging performance and convenience

To choose a USB charger, it is important to check these 4 factors related to charging performance and ease of use.

If you understand these factors, you will be able to see the optimal charger for your devices. “Output (W)”, “Fast charging standards”, “Port type and number”, and “Size and shape”. We will explain each point in detail to make it easy for beginners to understand.

Output (W) – The key to charging speed

The “output (W)” of a USB charger is a factor that greatly affects charging speed.
“W (watts)” is a unit that indicates the amount of power that the charger can supply at once.

The larger this number, the faster you can charge your device.

For example, smartphones generally can be rapidly charged with 20W to 30W, but tablets require 30W or more, and laptops with high power consumption require 45W to 100W or more.
Check the wattage required by your devices and choose a USB charger with an output greater than that.

Also, if you want to charge multiple devices simultaneously, you need to choose a charger with a total output greater than the sum of the wattage required by each device.

However, as explained in the port section, when using multiple ports, the output is distributed to each port, and the maximum output of each port may decrease.
Choosing the right output charger will shorten charging time and reduce stress in your daily life.

Fast charging standards – The importance of confirming compatibility (USB PD, QC, etc.)

To maximize the performance of a charger, it is very important to confirm compatibility with fast charging standards.
Fast charging standards are like agreements that allow devices, chargers, and cables to communicate with each other to efficiently and safely deliver power.

Representative standards include “USB Power Delivery (USB PD)” and “Quick Charge (QC)“.

USB PD is widely used in USB Type-C ports and can charge a wide range of devices, from smartphones to laptops, at high power.
Quick Charge is a standard mainly adopted by Android smartphones with Qualcomm processors.

Also, the device, USB charger, and USB cable must all support the same fast charging standard to perform fast charging.

Standard name	Features	Main compatible device examples
USB Power Delivery (PD)	Can charge much faster than standard charging, can also charge laptops	iPhone 8 and later, many Android smartphones, many tablets, many laptops
Quick Charge (QC)	Can quickly charge Android smartphones easily	Many Android smartphones (depending on the model), some tablets

It is very important to know which fast charging standards your devices support.
“I don’t know if my device supports it, but it looks fast, so I’ll just choose this one” is not a good idea. Please check once.

This GaN material is more efficient and suppresses heat generation than conventional silicon, making it possible to make the charger body smaller and lighter.
This makes it easier to carry high-output chargers, reducing the burden of carrying a large AC adapter for your laptop, and improving convenience.

Understanding the fast charging standards supported by your devices will allow you to choose the best combination of charger and cable and significantly reduce charging time.

Ports – Selection criteria for type (Type-A/C) and number

When choosing a USB charger, “the type and number of ports” greatly affects usability.
The main shapes are USB Type-A, USB Type-C, and Lightning.

USB Type-A is a traditional, square-shaped standard port commonly found in older devices and chargers. (Output only)

Lightning is Apple’s proprietary port, mainly used for the input port of iPhones and certain iPads.

On the other hand, USB Type-C is a modern, oval-shaped port that can be plugged in smoothly without worrying about the orientation, and is widely adopted by the latest smartphones, tablets, and laptops. (Both input and output are often used)

It is important to check whether your devices have one of these three ports, or other shapes such as Micro USB Type-B.

Port name	Brief description of shape	Main features	Input/Output	Main compatible device examples
USB Type-A	Square	Traditional standard port	Output only	Old chargers, PC ports
USB Type-C	Oval, symmetrical	Can be plugged in without worrying about orientation, supports high-speed data transfer and high output (USB PD)	Both input and output	Latest smartphones, tablets, laptops, earphone cases, etc.
Lightning	Apple’s proprietary, slender shape	Apple’s proprietary port	Basic input	iPhone (before 14), some iPads, AirPods cases, etc.
Micro USB Type-B	Small, trapezoid-like shape	Standard port for older small devices, still in use in some cases	Input only	Old Android smartphones, mobile batteries, Bluetooth speakers, etc.

Confirming this port is essential to choose the right cable.
Make sure you look carefully at the port of your device so that you don’t end up with “I want to charge it, but the port doesn’t fit!”

Confirm the type of port on your device, choose a charger with the appropriate port, and charge your devices efficiently.

Size and shape – Portability and installation location

The “size and shape” of a USB charger is a point to consider depending on how you use it.

If you often carry it around, it is convenient to choose a compact and lightweight model that does not get in the way in your bag or pocket.
A type with a foldable plug is even more portable, as it prevents the charger from damaging other items in your bag and makes it easier to carry.

On the other hand, if you use it fixed in a specific place such as at home or in the office, it is also good to choose a model with multiple ports or a design that blends in with the installation location, even if it is a little larger.

This GaN material is more efficient and suppresses heat generation than conventional silicon, making it possible to make the charger body smaller and lighter.
This makes it easier to carry high-output chargers, reducing the burden of carrying a large AC adapter for your laptop, and improving convenience.

Considering your main use case (for carrying around or for fixed use), and taking into account the space at the installation location, choose the optimal size and shape of USB charger.
Choosing a shape that is easy to use will make charging even more comfortable.

Essential checks for safe use

When choosing a USB charger, charging performance and ease of use are important, but the most important thing is to check for safety to protect your devices and yourself.

Confirming the safety standard “PSE mark”

The “PSE mark” is a proof of safety standards stipulated by the Japanese Electrical Appliance and Materials Safety Law.
This mark indicates that the product meets the strict safety standards set by the country.

It is mandatory to display this mark on electrical products manufactured or imported into Japan, especially on AC adapters such as USB chargers.
This mark is displayed on the product body or packaging.

PSE mark display	Safety	Legality in Japan
Displayed	Safety has been confirmed based on the law	Sale and use are permitted
Not displayed (including similar marks)	Safety based on the law has not been confirmed	Sale and use are not permitted

To protect your valuable devices and prevent unforeseen accidents such as fire, be sure to choose a product with the PSE mark when purchasing a USB charger.

Check for protective functions such as overcharge and overheat prevention

USB chargers have various protective functions to protect your devices and the charger itself from trouble during charging.
It is essential to check whether these functions are equipped to judge safety.

Representative protective functions include overcharge prevention, which automatically stops charging when the device’s battery is fully charged, overheat protection, which stops charging when the charger or device temperature becomes abnormally high, short-circuit protection, which prevents circuit shorts, and overcurrent protection, which prevents abnormally high current flow.

Protective function	Function
Overcharge prevention	Suppresses battery degradation
Overheat protection	Prevents fire and equipment damage
Short-circuit protection	Prevents equipment damage due to short circuit
Overcurrent protection	Protects equipment from abnormal current

To maintain a safe charging environment and use the USB charger with confidence for a long time, it is important to check whether these protective functions are described in the product specifications.

Points to select products from reliable manufacturers

To choose a safe product from the many USB chargers available, it is also a very effective point to choose products from reliable manufacturers.
Manufacturer selection greatly affects the reliability of product quality and safety.

Reliable manufacturers set strict safety standards from the product development stage and thoroughly conduct safety tests based on the law.
They reliably obtain necessary PSE marks and other certifications and disclose that information.

Also, detailed specifications and safety functions related to the product, and a support system for troubleshooting are also well-established.

Checkpoints for reliable manufacturers	Content
Safety certification acquisition status	Whether or not it has acquired and displayed the PSE mark and other safety certifications stipulated by the country
Product information details	Whether or not output specifications, compatible standards, and safety functions are clearly disclosed
Customer support	Whether or not there is an inquiry desk and a warranty system, and whether or not prompt response can be expected
Market evaluation and track record	Whether or not there is a long sales track record and high ratings from other users (word-of-mouth, reviews, etc.)

Instead of jumping on cheap products with unknown origins, choosing products from manufacturers that are clearly committed to safety and have earned the trust of many users is a smart choice to ensure safe and comfortable charging in your daily life.

Final check for choosing the optimal USB charger

Based on what you have learned in the previous steps, here are some points you must check.
The most important thing I want to tell everyone is “safety” and “whether it suits your usage scene”.

Here, we will briefly review the 6 steps of important points and explain how to make a final judgment based on your specific usage scene.

Please do not skip this final check to ensure that you can use your devices safely and comfortably.

Important points review

First, let’s revisit the 6 steps we’ve taken to choose the optimal USB charger.

By keeping these 6 points in mind, you will greatly increase your chances of finding the optimal USB charger.
In particular, it is important to prioritize checking the PSE mark and protective functions related to safety.

Thus, after mastering the basics of selection, choose the charger that perfectly matches your “I want to use it like this” specific image.
This is the final step to finding a charger that you can use comfortably and for a long time.

Frequently Asked Questions (FAQ)

Is choosing a wireless charger different from choosing a wired charger?

Yes, the points to consider when choosing a wireless charger and a wired charger are slightly different.
When choosing a wireless charger, first confirm whether your smartphone supports the international standard “Qi (Chi)”.
Wired chargers mainly focus on wattage and fast charging standard compatibility, and the type and number of ports, while wireless chargers need to consider whether it is a pad type to place your smartphone on while charging or a stand type to hold it up, and whether it can charge multiple devices simultaneously (e.g., “2 in 1”).
Charging speed tends to be slower than with wired charging, but the latest standard-compliant products can charge at high speed.
Also, be careful as it may not be able to charge depending on the case you are using.

How long can a USB charger be used? Are there any signs of its lifespan?

The lifespan of a USB charger generally ranges from 3 to 5 years, depending on the product quality, frequency of use, and storage environment.
If the charger is deteriorating, you may notice signs such as slower charging speed, abnormal overheating during charging, or strange noises from the body.
If you notice any of these abnormalities, it is recommended to replace it with a new charger for safety.
Continuing to use it against your better judgment may lead to failure or unforeseen accidents.

Are there any other safety certification marks besides the PSE mark?

The PSE mark is the most important safety standard proof for selling and using electrical products in Japan.
However, there are various other safety certifications in the world.
For example, the CE mark is a safety standard conformity mark mainly required for distribution within the EU (European Union).
The UL certification is a standard set by the American Insurance Safety Laboratory and is given to products that have passed very strict tests.
Products with these overseas certifications can also be said to meet a certain level of safety.
To use USB chargers safely in Japan, be sure to first check for the PSE mark.

The article says that cables are also important. What are the points to consider when choosing a cable?

Yes, as mentioned briefly in the article, choosing the right charging cable is just as important as choosing a USB charger to maximize its performance.
Especially when fast charging, the cable, charger, and device must all support the same fast charging standard (e.g., Power Delivery).
The cable also has specifications such as “〇〇W compatible” and “〇〇A compatible” listed on it, so it is important to choose a cable with specifications that meet or exceed the power required by your charger and device.
If you use a cable that is not compatible, you may not be able to achieve the original charging speed even if you choose a high-output charger.
Choose a cable from a reliable manufacturer with clearly stated specifications.

What is the best way to choose a USB charger for travel and business trips?

When considering carrying it around for travel and business trips, portability is the most important thing to consider.
Choose a compact and lightweight model that does not get in the way in your bag.
A model with a “foldable plug” that can be folded into the body is even more convenient, as it prevents the charger from damaging other items in your bag.
Also, if you often carry multiple devices such as smartphones and tablets, choose a model with multiple USB ports so that you can charge them simultaneously and use your time effectively.
However, models with multiple ports tend to be larger, so consider the balance with portability.

I have multiple chargers. Is it okay to use them interchangeably?

It is generally okay to use your multiple USB chargers in combination with different devices and cables.
However, it is important to understand the “output wattage”, “compatible fast charging standards”, and “port type” of each charger.
It is okay to use a charger with an output higher than the wattage required by the device, but using a charger with a significantly lower output will take a long time to charge.
Also, as explained in the article, be sure to use products that have safety certifications.
If they are safe, you can use them interchangeably depending on the compatibility with the device.

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