How does fast charge work?

Operating system, screen size, how good the camera is and so on. When choosing a phone, there are many factors to consider. And lately, another thing has come up, that you need to consider; namely, fast charging. A technology that is, slowly but steadily, emerging from manufacturers, because who doesn’t want to be able to charge their phone in no time?

Imagine in the scenario that you wake up in the morning, have an important day ahead of you, and realize that you only have 4% battery! Then it is worth gold to be able to charge the phone in fifteen minutes. Into the stage comes a fast charge (applause from the audience).

But how does fast charging work? And how come not ALL phones have this?

Snabbladdning fast charge

Charging the battery – the basics

Let’s start with the basics. All smartphones have a battery (no shit Sherlock) and these batteries supply power in basically the same way. Cells catalyze chemical reactions that drive electrons to the negative terminal of the battery. In disposable batteries, this chemical reaction occurs once. In the batteries that mobiles have, this reaction is reversible. Therefore, the battery can be recharged again and again.

Quick charge/ Fast charge

Fast Charging, or quick charing as it is also called, is exactly what it sounds like. It is a way to charge the phone in a much shorter time than it usually takes. This is a feature supported by some smartphones and tablets.

The reason why it takes so long to charge a mobile phone the usual way is because of the limited amount of power that a regular charger can transfer to your device at one and the same time. This is usually 5W or less.

The limited amount of power is a design decision that allows manufacturers to keep costs down while ensuring that the fairly small batteries in your devices are not destroyed due to overheating.

However, many phones can handle more than 5W, thanks to internal circuits that set a wattage limit that can reach your battery at one and the same time. Quick chargers take advantage of this by adjusting the voltage or current and in some cases both. This way, the charger can deliver up to 20W, or sometimes even higher if your device supports the technology.

Many manufacturers that make fast-charging products have created a way for the device and the charger to conduct a dialogue about how many watts the device is ready to receive.

This means that even if a charger says that it can supply a certain amounts of watts, it does not have to mean that the cellphone is charged much faster than usual since the cellphone cannot receive the current.

Works better with low battery

Fast charging works much better when you have a low battery level and you need a quick way to recharge a part of the battery. Charging speed tends to decrease significantly as the battery begins to get fully charged. So don’t expect to be able to go from completely empty to fully charged battery in no time.

Is fast charging harmful to the phone?

With higher voltage strength comes more heat, which causes the battery to swell a little. Therefore, devices without enough internal room for the battery can be damaged if the battery is charged too fast.

It is important to remember that the higher heat can also be more abrasive to your battery, which can degrade its service life. Due to these factors, fast charging is not a standard delivery.

What are the types of quick chargers?

There are many suppliers of fast chargers. With an Apple product, you can fast charge with USB PD. This is an industry standard used by quite a few devices and requires no special cables or wall adapters. Samsung has Fast Charge and Oneplus has Dash Charge, both of which are popular fast chargers. Motorola offers TurboPower as its fast charging option. But the one most likely to be used is Qualcomm’s Quick Charge, which is compatible with a large number of Android devices.

The future of fast charging

Fast charging is something that is highly demanded by consumers, which means that technology is on the rise. Progress is constantly being made in adapters, integrated circuits and cables. This means that a future where you can charge your phone in minutes, rather than in an hour, is closer than you think. An increase in suppliers for fast chargers has enabled us to find more chargers that are smaller in size and more powerful than ever.

For those of us who work with telephony for companies, we think the trend looks promising and we like the idea that we can charge the phone super fast and then be able to talk more on the phone.

Want to know more about how to save on your mobile battery?

Then you might want to check out some of our other blogs about mobile battery:


By Elin Gunnarsson
Content Manager
In a time of "it must happen now" it is of the utmost importance to have the right communication solutions.

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