What is fast charging in mobile phones? As the name implies, it is any type of high-speed battery-charging system implemented in a mobile phone to reduce the time it takes to fill up the battery. With regular charging, sometimes it takes a whole of three hours to charge up a phone fully. High-speed charging solutions cut that time down dramatically.
There are different solutions in the market, with many manufacturers often developing their own proprietary system and going by a unique brand name. But whatever the specifics of these solutions, they all work by a broad principle. Note also that apart from the custom solutions by each brand, there are industry standard charging solutions that some brands have adopted.
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How Fast Charging Works
Fast charging in mobile phones works by pumping extra electrical charges into the phone, usually in two phases. The first phase happens between 0 and 80%, approximately, and happens much faster than the second phase.
The second phase is slower for safety reasons, because it is a critical period when the battery already has a lot of charge and is less stable. This means, accidents can happen if charging continues at the initial speed, so designers build the charging solution to slow down here. That is why your phone takes much longer to go from 80% battery to 100% than you’d like. But it is for your safety.
That is also the reason why some phones stop charging at 80% under certain conditions e.g. if the weather is hot. The in-built fail-safe system cuts off charging to keep the phone cool and stable.
Different Fast Charging Technologies from different phone makers
There are different proprietary fast charging systems by different phone brands and they are not generally compatible with one another. For example, a fast charger from Samsung may not be fully compatible with one from Google Pixel. Let’s explore the different types.
Quick Charge by Qualcomm
Qualcomm’s fast charging solution is called Quick Charge. The latest iteration, Quick Charge 5.0 tops up compatible devices from 0-100% in 15 minutes. Any phone brand can license this solution for use in their products that are powered by a compatible Snapdragon chipset.
MediaTek Pump Express
Pump Express is MediaTek’s answer to Qualcomm’s Quick Charge. It is specific to smartphones powered by a compatible MediaTek chipset.
USB Power Delivery
USB Power Delivery is an industry standard charging protocol designed for both cellphones and laptops. If your phone has a USB-C port and supports USB-PD, you are not limited to using your phone’s fast charger but can also use compatible 3rd party chargers to top up your battery quickly.
USB Power Delivery 3.0 is capable of delivering up to 100W charge, though most cellphone brands have not maxed it out to its fullest capacity yet. While your smartphone does not need this much power, laptops and other devices do. Remember, we mentioned earlier that this is an industry-wide quick charging solution for USB devices, whether they are phones, tablets, laptops, etc. Samsung has utilized USB-PD 3.0 to deliver 45W in the S24 Ultra.
In addition to their proprietary charging solutions, many phone makers include USB Power Delivery support in their devices, such that any phone from another brand that supports PD can take advantage of its fast charging capabilities.
Charging in Samsung Phones
Samsung does not have a proprietary charging solution. Instead it uses an available industry solution called USB Power Delivery (discussed above). Most mid-range and premium flagship Samsung smartphones have a mere 25W charging based on PD. The company’s fastest charging solution is a 45W charger that can do 0-70% charge in 30 minutes, as seen in the Galaxy S24 Ultra. This charging system is based on Power Delivery 3.0.
Charging in Google Pixel Phones
Like Samsung, Google Pixel phones do not have a proprietary charging solution and also uses the universal Power Delivery technology.
Charging in iPhones
Third time is a charm, because rather than develop a proprietary charging solution, Apple also simply uses USB Power Delivery. The iPhone 16 Pro Max uses PD 2.0 which charges the battery up to 50% in 30 minutes.
if you ever were bothered that Samsung phones, iPhones, and Pixel phones have the slowest charging speeds in the industry, you now know that it is because they use USB Power Delivery. Of course, for some reason, they are not squeezing out the fastest possible speeds out of it. So, the ball still stops at their desks.
And yes, you can charge your iPhone with a Samsung charger and enjoy fast charging speeds (see my video on the subject), thanks to the Power Delivery standard that both brands use.
SuperVOOC by OPPO
OPPO’s charging solution is called SuperVOOC. Their 150W SuperVOOC solution charges a 4,500mAh battery from 0-50% in just 5 minutes, and 0-100% in just 15 minutes, while their new 240W SuperVOOC solution does 0-100% in a mere 9 minutes.
FlashCharge by Infinix
Infinix‘s fast charging solution is called FlashCharge. The company’s 160W charger has demonstrated taking the phone battery from 0% to 100% in 10 minutes.
HyperCharge by Xiaomi
Xiaomi’s charging technology is branded HyperCharge. The 120W HyperCharge charger takes about 20 minutes to fill up a battery.
Questions & Answers
Are fast charging cables different?
As far as the connecting ports are concerned, they are no different from regular charging cables. But on the inside, the components and design may differ.
Can fast charging damage your battery?
The problem with fast charging is the amount of heat generated, which is bad for the battery. However, speedy charging solutions have fail-safe systems built in to terminate the charging should heat like up. So you have nothing to worry about.
Can fast charging damage iPhone?
Fail-safe systems exist to protect your Apple iPhone when fast charging.
How long should fast charging take?
It depends on which solution you are using. For example, 18W takes over an hour to go from 0-100%. 33W takes less than an hour. 65W takes about 30 minutes. 120W solutions do it in about 15 minutes.
Is fast charging worth it?
Definitely. We live in a fast-paced world and no-one wants to spend two or three hours charging their smartphones. The convenience of being able to top up your cell phone battery in a few minutes is definitely worth it.
Which iPhones support fast charging?
All models from iPhone 8 support 15W fast charging and above.
Why does fast charging heat up phone?
Speeding up charging in a phone works by pushing in more electrical charges than usual to shorten the charging time, applying extra stress on the battery, and so causing discharge of heat.