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fastest charging explained

(Topic created on: 03-20-2020 03:37 PM)
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hedgehog
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What Is Fast Charging?

Life in the Fast Lane

Being able to quickly charge your phone or tablet can mean the difference between hours of care-free use or scrambling to find the nearest coffee shop for a power outlet. Fast charging is an increasingly popular feature that allows you to power up your phone in just a fraction of the time it takes to do it the old-fashioned way. But not all phones use the same type of fast charging—and not all chargers support the various standards. Here's what you need to know to make sure you're getting the fastest charge possible.

Understanding Fast Charging

The output of a charge is measured in amperage and voltage. Amperage (or current) is the amount of electricity flowing from the battery to the connected device, while voltage is the strength of the electric current. Multiplying volts by amps gives you wattage, the measure of total power.

To make a device charge faster, most manufacturers either boost the amperage or vary the voltage in order to increase the amount of potential energy going to a device. Most fast charging standards dynamically vary the voltage rather than boost the amperage.


Standard USB 3.0 ports output at a level of 5V/1A for smaller devices like wearables. Most phones and other devices are capable of handling 5V/2.4A. For fast charging, you're looking at something that bumps the voltage up 5V, 9V, 12V, and beyond, or increases amperage to 3A and above.

Keep in mind, your phone will only take in as much power as its charging circuit is designed for. So even if you have it plugged into a 5V/3A adapter, if it's only able to handle 5V/2.4A, that's the rate at which it will charge. For fast charging to work, you need a phone or other device with a charging circuit capable of using one of the fast charging standards, and an adapter and cable enabled for that same standard.

Type of Fast Charging

Qualcomm Quick Charge

The most common fast charging standard is Qualcomm's Quick Charge because of the widespread nature of the company's chipsets. Quick Charge 2.0 and 3.0 are the two type of fast charging you're most likely to see now, with Quick Charge 4+ on the horizon. Each standard is backward compatible with the previous one, so older cables and adapters will still work.

Quick Charge 2.0 bumps up the voltage at intervals of 5V, 9V, and 12V. Quick Charge 3.0 can boost voltage across a broader range, varying dynamically from 3.2V to 20V, though peak power for both standards is 18W. That means phones like the LG G6 can reach an 80 percent charge in just 35 minutes.

Quick Charge 4+ narrows the voltage range while pumping up the amperage. You get 5V at between 4.7A to 5.6A, or 9V at 3A. Quick Charge 4+ devices use USB-C ports and are compliant with USB Power Delivery (see the section Beyond Your Phone below). They also have a second power management chip, allowing up to 28W of power without overheating. We haven't tested any Quick Charge 4+ phones yet, but theoretically it allows them to go from zero to 50 percent charged in just 15 minutes.

Click here for a complete list of Qualcomm Quick Charge-compatible devices.

MediaTek Pump Express

Certain MediaTek-powered phones use the company's Pump Express standard. Like Qualcomm Quick Charge, Pump Express comes in different versions on different devices.

Pump Express+ and Pump Express 2.0 are the older standards. Both focus on varying voltage to increase charging speed, while bumping current up to 3A or 4.5A. With Pump Express+ you get fixed intervals of 5V, 7V, 9V, and 12V, which means you can charge the average MediaTek-powered phone's battery from zero to 75 percent in 30 minutes.

Pump Express 2.0 has a wider range between 5V and 20V, on par with Quick Charge 3.0. Pump Express 3.0 supports USB-C PD and varies the voltage in a narrower range, between 3V to 6V, while upping the current to 5A, potentially letting a device go from zero to 70 percent in 20 minutes.

The newest Pump Express 4.0 standard supports 5A of current as well as USB Power Delivery 3.0 with greater efficency and better heat management. It works with any smartphone containing a MediaTek Helio P60 chipset and is able to charge to 75 percent in 30 minutes.

Samsung Adaptive Fast Charging

Samsung's Adaptive Fast Charging isn't as common as it used to be, but works in a similar manner to the above standards by bumping up voltage and/or amperage. As you might imagine, it only works with certain Samsung devices and with compatible adapters that push out 5V/2A for older micro USB phones and 5V/3A or 9V/2A for USB-C, along with compatibility for USB Power Delivery. Phones like the Samsung Galaxy Note 8 (which can charge to 50 percent in 40 minutes) support both Adaptive Fast Charging and Qualcomm Quick Charge, making it easier to find a compatible charger.

Oppo Super VOOC Flash Charge

VOOC is Oppo's proprietary fast charging standard and naturally, you'll only find it on compatible Oppo phones like the Find 7a and R7. Unlike Quick Charge, VOOC operates by increasing current rather than voltage. With a compatible adapter and cable, the flash charge circuit is able to transfer a 4A current at 5V, letting your phone charge from zero to 75 percent in 30 minutes. Naturally, it has a thermal management chip to keep temperatures low while charging, so you don't have to worry about overheating.

OnePlus Dash Charging

Dash Charging on the OnePlus should sound familiar, because it's licensed form Oppo, so it works the same as VOOC, bumping up amperage to 5V/4A to achieve an output of 20W. On a phone like the OnePlus 5T, you can charge up to 60 percent in 30 minutes.

Huawei SuperCharge

Like most charging technologies, Huawei SuperCharge works by varying voltage and amperage. With compatible adapters and cables, you're able to get an output of 5V/1A (5W), 5V/2A (10W), 9V/2A (18W), or 4.5V/5A (22.5W). You can charge to 58 percent in 30 minutes on compatible devices like the Mate 10 Pro.

Anker PowerIQ

Anker's PowerIQ fast charging is a bit different in that it doesn't come built into the phone itself. Rather, it works with most phones that have fast charging circuits. PowerIQ identifies the connected device and varies voltage output for optimized charging speeds at intervals of 5V/1A, 5V/2.4A, 5V/2A, 9V/2A, and 12V/1.5A, essentially the same as Qualcomm Quick Charge 2.0.

You'll find PowerIQ on many Anker power banks and AC adapters. Power IQ 1.0 can output at 12W, while Power IQ 2.0 can handle up to 18W. For a phone like the Galaxy S8, you're looking at a charging speed of 2 hours to 100 percent for IQ 1.0, and 1 hour, 30 minutes for IQ 2.0.

What About Wireless Fast Charging?

Wireless charging is convenient, but it can be slow. Most wireless chargers that lack fans or cooling systems are limited to fairly slow charging speeds of 5V/1A. But various companies now offer fast wireless charging pads that come with built-in fans to dissipate heat, allowing you to charge at speeds nearly on par with a cable.

Voltage and amperage depend on the charging pad in question. Once again, you'll want to make sure that your phone and your wireless charging pad support the same fast charging standard. Also keep in mind you'll need a wall adapter plugged into the pad that supports fast charging as well (these should come with the pad, but in case you lose them, you can't simply replace them with any old adapter and cable you have lying around).

Beyond Your Phone

For laptops, the situation is a bit different. USB Power Delivery isn't so much fast charging as it is a standard that determines if an adapter or portable power bank is capable of charging a laptop or other high-powered device. With USB-C input/output ports becoming more prevalent, it's now possible for adapters and portable power banks to charge demanding devices that require an output of 18W or more. The Power Delivery spec allows a device to be charged at a maximum current of 5A or 100W.

The newer Power Delivery 2.0 is better able to adjust voltage and amperage configurations, to supply power at different intervals depending on the needs of the device. A smartphone would get 5V/2.4A, while a laptop might get 20V/5A to achieve a sufficiently high wattage (100W). USB PD 3.0 adds more enhancements for power delivery, with outputs at 7.5W, 15W, 27W, and 45W, each with its own voltage and amperage configurations.

What You Need

Depending on the device you have, the fast charging standard you're able to use will vary. Check what your phone supports, then look at your wall adapter to see if it supports the same standard (they're usually labeled). Then make sure your cable is compatible (you're best off using one the one that come with your phone or adapter


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vroshni123
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Tech Talk
Fast charging was explained very well in this topic
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