# Super-fast charging technology: Not as fast and as good as you think

Tram Ho

In the context of smartphones becoming more and more intimate, having to use and charge it daily has become evident. Hitting the minds of busy users, phone manufacturers have quickly launched super-fast and wireless chargers with attractive advertising such as taking less than a few tens of minutes to charge each. days that still ensure phone life.

These ads are basically not wrong, but to get the right idea of ​​fast charging, start with the most basic concepts.

What is fast charger, super fast charger?

Many people still remember the law of classical physics when they were in elementary school: The electric current is the directional change of the positively charged particles. By that definition, charging is a form of bringing charged particles from a power outlet to the battery in a phone. Fast charging means getting charged particles into the phone battery as quickly as possible.

However, whether or not to charge quickly depends on two factors including the phone and the charger. High-capacity chargers cannot ‘push’ all charged particles into the phone battery, and conversely, strong batteries cannot absorb the limited number of particles from a low-capacity charger.

The iPhone 11, for example, sells a 5W charger but supports greater power absorption. If you buy an 18W adapter, you can charge it from 0% to 100% in half the time it takes to use Apple’s default charger.

The capacity of the charger is measured in Watt (W) and it is calculated using the familiar formula learned in level 2: P = UI. In which, P is Power measured in Watt units, U is Voltage measured in Volt (V) and I is Current is measured in Ampere (A).

For ease of visualization, the power is the same as the water flowing into the device you’re charging, where V is like water pressure and A is the width of the faucet. Both of these factors affect the speed of the flow.

With a battery, you can picture it like a pot you need to fill with water. You can use a water spray gun (normal charger), a sprinkler hose (quick charge) or collect spring water (wireless fast charger), but the water pressure and water flow will have an impact on how long you have to wait to get a full basin of water.

The current fast charging technology

Right at the time of writing, Qualcomm has just announced its fifth generation fast charging standard with the promise of helping to charge from 0% to 50% in less than 5 minutes.

OnePlus also has a fast charging technology called Warp Charge, which is advertised as requiring only 10 minutes of charging to use wireless headphones within 10 hours.

In the middle of this July, Oppo has revealed 125W fast charging technology that can fully charge a 4,000mAh battery in just 20 minutes.

In general, manufacturers are trying to build a fast charging technology where the hot part is in the charger and try to keep the phone battery as cool as possible. That’s how fast charging does not affect the components inside a smartphone.

The specific technologies were not disclosed by the manufacturer, but it was basically a way of arranging and controlling the IC inside the charger and battery to ensure fast but not over-standard heat. In addition, to make charging speed faster, manufacturers create dual batteries in the phone and the charging process is the process of charging two batteries at the same time, leading to faster speed.

The material used to make the charger has also been improved by manufacturers using GaN (gallium nitride) instead of silicon. Basically, GaN is an inorganic, semiconductor compound that has been studied and used in LEDs since the 90s of last century.

Today’s manufacturers are starting to see the benefits of GaN as it reduces costs, reduces the size of the charger, and allows current to flow much faster than silicon. It is even used to make smaller chargers for laptops today.

Quick charging is not completely fast

Actual fast chargers only allow fast charging from 0% to a maximum of 70%, after which it will slow down to maintain a stable voltage and not overheat the phone.

As recommended by Battery University, fast charging should only fill the battery from 0% to 50% and the internal battery cells (cells) must maintain a balance to avoid the current from putting pressure on the weak battery blocks, lead to battery bottle.

In May, Oppo had to admit that wireless fast charging technology reduced the maximum capacity of the battery to 70%, in the same charging cycle, usually only reduced the battery capacity to 90%.

Obviously, putting the battery under high and constant pressure will make the battery pack faster. That is also why big companies like Apple or Samsung are not keen on fast charging technology or super fast charging.

However, other manufacturers persist in pursuing fast charging technology as a selling advantage. Because, with the new phones launched every year, even every month, there is nothing to worry about whether the battery is fast or not.

According to Gizmodo

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Source : Genk