USB Cable or Adapter: Why is Your Fast Charger not Fast Charging

Carrie Tsai - Neway
11 min readSep 4, 2020


Source: USB Cable or Adapter: Why is Your Fast Charger not Fast Charging

Today’s smartphones aren’t traditionally mechanical. From screen to processing power, they are being endowed with brand-new features and techs in order to make themselves competitive. You can see the new phone techs coming recently such as Face ID lock screen, fast charger, mobile 5G, GPU acceleration, NFC, and a pop-up camera. Among all the latest cool phone techs, fast charging is the one that is widely adopted as a response to increasing phone usage and a larger phone.

Since smartphones are being used more frequently by individuals per day and are getting larger, fast charging has been a necessity of smartphones, which allows for a quick charge in minutes instead of hours. So far, this technology has been adopted by most smartphone brands in their latest flagship phones. 18W fast charging has been the basic standard while 40W and much faster charging are available now.

Now you may be ready to enjoy the benefits of the fast charging technology. However, you may bog down to confusion about whether the fast charging speed depends on the fast charger or the USB cable, which makes it difficult for you to choose the right charging accessories for a fast phone charges.

Well, in fact, the fast charging speed is dependant on both the fast charger and the USB cable. Keep reading to find how they work to affect the charging speed. Also, the following will provide you with useful tips and powerful charging accessories to better go towards fast charging.

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How Does the Fast Charger Work to Turn up the Charging Speed

The fast charger, also called the fast charging head, can enhance the charging speed. But how does it work? Well, exploring how the fast charger makes the fast charging speed is to explore how the charger, in general, affects the charging speed.

The charger acts as the source of the power output. It determines the magnitude of the voltage and current. Current (or Amperes) is the amount of electricity being transmitted while voltage is the strength of the current (the force that pushes the current forward). The current multiplied by voltage is the maximum output power (Watts, W). When charging a phone, a certain amount of current flows from the power source, through the charger, to the phone or other connected devices.

Since the charger determines the current and the voltage, it determines the maximum output power and thus the charging speed. In technical, the general principle is the higher the output power, the faster the charging speed.

Chargers are always marked with the label indicating V/A which in fact shows the power of it. For instance, when you see 5V/3A on your phone charger, it means that the charger can deliver the maximum 15W of power. If you replace your 5V/3A phone charger with 3V/6A, the new charger can deliver the maximum 18W of power when charging your phone, making the charging speed faster.

So when it comes to the fast charger, at the simplest level, it actually brings up fast charging speed by increasing the power, the number of watts that are transported to a phone’s battery. As the source of the power output, the fast charger significantly turns up the charging speed, leading to much more efficient charging.

Currently, the 18W fast charger has been typically the basic charging standard of the vast majority of mobile phones. Some flagship phones are even equipped with 40W, 80W, and 100W fast chargers available. Newly-released smartphones coming with fast chargers have been the mainstream.

How Does USB Cable Impact the Charging Speed

The fast charger can affect how fast your phone’s battery fills up to 100%, but it’s not the only determining factor. USB cable also has an impact on the charging speed since it serves as the intermediary responsible for connecting the phone and the charger for current transmission.

It can be more easily understood if you compare the USB cable as a water pipe, the fast charger as a faucet, and the phone battery as a bucket. To charge the phone is equivalent to fill the bucket with water. The faucet needs to be connected to the bucket via the water pipe to pour the water into the bucket. Similarly, the fast charger which doesn’t directly connect to the phone also needs to be connected to the phone through the USB cable to transport power to the phone’s battery.

That said, the USB cable also determines the charging speed. There are several factors of the USB cable that can affect the charging speed including the length, the gauge (thickness) of the internal wire as well as the quality of the wire. In general, if all the other factors are maintained constant, the longer the cable, the longer the charging time. On the contrary, the shorter the cable, the shorter the charging time, and thus the faster the charging speed.

As a conductor for transporting current, USB cable offers some resistance when the current is flowing through it. The smaller the resistance, the better the conductivity performance, and thus the faster the charging speed.

The resistance depends on the gauge and the length of the USB cable. In general, if the gauge of the internal wire is kept constant, the shorter the length, the smaller the resistance, and thus the quicker the charging speed. If the length is maintained the same, the larger the gauge (thickness/cross-sectional area) of the wire, the smaller the resistance, and thus the faster the charging speed.

Of course, the quality of the USB cable also has an impact on the charging speed. Bad quality cable slows down the charging speed since it’s equipped with no or just a few copper-core wires, which reduces the conductivity performance and in turn slowing down the charging speed.

The Micro USB cables on the current market generally support 2A while the USB Type-C can transmit 3A and higher current. Since fast charging has been adopted by almost every flagship mobile phone, the most USB cables on the current market come with fast charging standards and support fast charging, leading to fast charging speed.

Also Read:

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Fast Charging Is the Result of the Compatibility of A Fast Charger, An USB Cable and A Device

It has been clear that both the charger and the USB cable determine the charging speed. Hence, the fast charging speed is dependent on both the fast charger and the USB cable which supports fast charging.

However, due to scores of different fast-charging standards that allow for varying power outputs and charge times, the optimal fast charging speed requires the compatibility of a particular fast charger, a particular USB cable as well as a particular connected phone.

That being said, on the one hand, there should be compatibility between your fast charger and your USB cable supporting fast charging. On the other hand, there should be a compatible phone which supports the same fast charging protocol as that of your fast charger and your USB cable. The compatibility among them allows for the optimal fast charging while the incompatibility leads to poor charging speed.

For example, if you have a 30W fast charger and use it to charge your phone which has the maximum battery power of 15W, the result is that the charger can only charge your phone with 15W power.

Simply put, fast charging is the result of the compatibility of the fast charger, the fast-charging USB cable, and the device supporting fast charging. Whether when you’re choosing a fast charger or when you’re picking a fast USB cable, you should pay close attention to the compatibility in order to achieve the optimal charging speed for charging your phone or any other device.

Ready to Fast Charging? You Should Start with A Powerful Fast Charger

Fast charging is indeed the inevitable trend since it allows for charging and recharging mobile phones and other devices in minutes rather than hours. As smartphones are becoming larger and are being used more frequently per day by individuals, charging them at a faster rate helps quite a lot.

When you charge up your phone quickly with a fast charger, you don’t have to waste a very long time waiting around your phone to be fully charged. You should start the fast charging of your phone with a powerful fast charger.

The following are a range of our powerful and excellent fast chargers options made for travel, indoor socket use as well as wireless use which can cover almost any of your needs with super-cheap prices. You can select the one which is compatible with your phone and other devices according to your specific needs. Also, these fast charger options allow for customization in design and logo. You can customize your unique one.

Important Note:

If a mixed color, the unit price will add 0.1USD. 0.025USD per unit for single color and single position logo.

Excellent Fast Charging Car Chargers

Our fast charging car chargers made for travel allow you to quickly charge your phone and other compatible devices in minutes while you’re driving car. Some of them support one or two USB Type-C ports while some support both USB-C and USB A ports, which enables them to connect to multiple devices at the same time and to be compatible with more devices.

Besides, they are capable of putting out 18W and higher power such as 30W, leading to very fast charging speed. Moreover, our fast car charger models are all certified by CE/FCC/ROHS and have OPP, OVP and OCP protections, making them safe to use. The following are our excellent models specs and prices:

Model IQ05 (product link) Specs & Price

Input: DC 12–24 V

Output1: DC 5V/3A ,9V/2A,12V/1.5A (Total QC3.0 18W)

Output2: DC 5V/2.4A (Total 30W)


Product Size: 28*18*74mm

Price: US$2.5

Model IQ07 (product link) Specs & Price

Input: DC 12–24 V

Output1: DC5V/3A ,9V/2A,12V/1.5A (Total PD 18W)

Output2: DC 5V/2.4A (Total 30W)

USB:1×USB and 1*Type-C

Product Size: 28*18*74mm

Price: US$3.1

Model KA03 (product link) Specs & Price

Input: DC 12–24 V(Total 30W)

Output1: DC5V/3A ,9V/2A,12V/1.5A (Total QC3.0–18W)

Output2: DC5V/2.4A (Total 30W)

Product Size: 24*27*73mm


Model KA04 (product link) Specs & Price

Input: DC 12–24 V(Total 30W)

Output1: DC5V/3A ,9V/2A,12V/1.5A (Total PD18W)

Output2: DC 5V/2.4A (Total 30W)

Product Size: 24*27*73mm

Price: US$3.3

Powerful Fast Chargers (for Socket)

For socket plug, our fast chargers are capable of delivering ultra-fast charging speed for your phone and other devices. They allow for 18W, 24W, 30W, 48W, and even 65W fast charging. Some are equipped with a USB port or USB C port while some even come with multiple ports, which allows for charging scores of different devices.

Moreover, they have great product quality certified by a number of certification standards such as UL, ETL, CB, CE, FCC, KC, PSE, ROHS and etc. They are also safe to use since they have OPP, OVP, and OCP protections.

Model QV05 GaN (product link) Specs and Price

Input: AC 100–240V 50/60Hz

Type-C Output:5V/3A,9V/3A,12V/3A,15V/3A, 20V/3.25A(single output 65W)

USB A Output:QC3.0 18W

USB: Type-C*1 USB*1

Product Size: 52*52*28mm


Model PST-18CPD-5000 (product link) Specs and Price

Input: AC 100–240V 50/60Hz

Battery Output: DC 5V/3A, 9V/2.0A, 12V/1.5A PD18W

Output A+C: DC5V/3.0A Max

Battery Capacity: 5000mA

Product Size: 72*59*31mm


Model DL04 (product link) Specs and Price

Input: AC 100–240V

Output: DC5.0V3A/9V2A/12V1.5A (Total PD 18W, Compatible QC3.0)

USB: Type-C

Product Size: 40*26*46mm US


Powerful Fast Wireless Chargers

Wireless chargers are also one of the most popular charging accessories for mobile phones since they liberate users from inconvenient cables and wires. A fast wireless charger is also a good choice to make your phone fill up in minutes. The following are our primary models. You can pick one to enjoy ultra-fast phone charging wirelessly.

Model WD07 Fast Wireless Charger Pad (product link)

This model is a pad supporting up to 10W wireless fast charging. It’s certified by Qi standard and FCC, making it safe and effective to use. Also, it comes with a high charging efficiency of more than 75%, allowing for fast charging speed.

Specs and Price

Input: C+M: 5V/2A,9V/1.67A

Output: 5W/10W

Charging Efficiency: ≥75%

Wireless Distance: 5mm



Model WP12 3in1 Fast Wireless Charger Stand (product link)

This model is very powerful since it supports wirelessly fast charging your phone, your watch, and your Bluetooth earphones at the same time. It has three stands for charging different devices respectively. It is capable of supporting up to 10W fast charging, allowing you to fast charge your phone wirelessly in minutes.

Specs and Price

Input: C 5V/3A,9V/2A/12V1.5A

Wattage: 10W

Apple Watch Input:5V/0.4A

Output:2W/3W/(5W/7.5W/10W )

Wireless Distance:2–8mm




Final Words

Fast charging coming with the fast charger is and will be the irreversible trend as it allows for charging and recharging your smartphone and other devices in minutes rather than hours. Since charging speed depends on both the charger and the USB cable, fast charging should be the result of the combination of the compatible fast charger, USB cable as well as the device.

A powerful fast charger is the source of the optimal fast charging. The fast charger you choose should be compatible with the corresponding USB cable and the connected device so as to achieve the optimal charging speed. The above range of our fast chargers are powerful, super-cheap, and widely-compatible for car use, wireless use as well as socket use, you can select the right one based on your practical needs.



Carrie Tsai - Neway

Carrie Tsai is part of team Neway and is always active to share her ideas of Neway. She enthusiastically dives each day into the depths of the mobile industry.