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Everything You Need To Know About Fast Charging

Last updated: 4 years ago
6 min read

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Running out of battery is frustrating. A few years ago, it would take at least 2 hours to fully charge. But thanks to modern advancements in charging technology, you can fast-charge almost all portable gadgets.

Samsung phone charging
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    But what exactly is fast charging, and what are the differences between modern fast charging standards? Let’s find out in the article below.

    What Is Fast Charging?

    Higher the number of watts, faster the charging.

    Now that’s the most basic answer. First, we need to understand what those numbers on the charger mean. Manufacturers usually advertise the watts, the total output power coming from the charger to your battery.

    However, Watts consists of:

    • Volts (the strength of the current)
    • Amperage (the amount of electricity going to your battery, also known as current)

    For example, a wall charger with 5 volts (V) 2 amperes (A) makes a total power of 10 watts (W).

    How Much Faster is it Compared to a Regular Charger?

    Usually, the gadgets that don’t support fast charging charge at the maximum power of 5W. This means that your gadget’s battery will charge at least 2 hours or more.

    New fast-charging standards support the power, ranging from 9W to 100W, while the latter is (currently) reserved for laptops (such as the newest MacBook Pro). This means that your headphone’s battery will charge up in less than an hour.

    How Does Fast Charging Work?

    It’s very similar to regular charging, just that the battery is filling up much faster. But because of that, the manufacturer must be more cautious of how the battery gets juiced up. If your battery is charging at constant power from 0-100%, it would most likely inflate or burst. This is why fast charging needs to take a more intelligent approach.

    When you read the advert, the manufacturer usually says that the battery can charge from 0-50% in 30 minutes, but they never say how long the battery charges from 0-100%. If you ever watched how fast your phone gets charged, you probably noticed that the quick charge feature only works until the battery is 80% full. After that, the charging gets slower to prevent the battery from getting damaged.

    Picture it like this: you have to pack your luggage for the vacation. At first, you have all the space available, so you can just throw things in it. But right before the luggage is almost full, you have to start searching for the remaining space inside the luggage, which slows down the packing process. The same thing applies to the fast charging battery.

    3 different charging ports
    Different fast charging standards support different fast charging speeds. USB-PD is the fastest charging technology right now.

    Is Fast Charging Safe?

    When designing new gadgets with support for Fast Charging, manufacturers take a lot of time to make sure the end-product doesn’t burst in flames when charging. As mentioned above, the feature only works until it reaches 80%, and it slows down afterward to protect the battery.

    Some standards are also making sure that the communication between the fast charger and the battery is spot on, giving you better-charging efficiency.

    Can You Fast Charge All Batteries?

    If you want to fast charge your headphones, they must support a specific type of fast charging. Therefore, you can’t just buy a more powerful wall charger and expect your battery to charge faster.

    Although even if you do that, your battery will still charge at the speed it was designed for. The controller chip in your device measures the battery’s cell voltage and amperage, adjusting the power delivery to your battery. Therefore you can use a faster charger on a non-fast-charging device, but it wouldn’t make sense.

    What Do You Need for Fast Charging?

    You need to make sure your device supports the fast charging feature. It’s usually labeled somewhere on the packaging or in a manual. Then check if your wall charger supports the same Fast Charging type as your device does.

    If not, you’ll have to buy a separate fast charger. Try not to buy the cheapest one, since some may not be able to handle power requirements. Even the cable itself is important since it can affect the fast charging speed.

    What is Wireless Fast Charging and How Does it work?

    Instead of transmitting the power via a USB port, the electricity is transferred between two coils. One is built into the charging pad, and another into your portable device (like a phone or earbud’s charging case). The most common protocol is Qi charging.

    When 2 coils are placed together (or within a specific range), they create an electromagnetic field. This generates an electric current that charges the battery.

    Wireless charging pad with MacBook and iPhone
    Regular wireless charging pads aren’t able to charge fast due to thermal limitations.

    It’s much more convenient to place your gadget on a wireless charging pad. But the charging process is usually slower. The reason is the heat generated by a charging coil. This is why most basic wireless chargers support the maximum power of 5-10W. If you want to get something more powerful, it needs to have some sort of cooling solution.

    The best wireless charging pads use the built-in fans to keep the charger from heating too much. OnePlus’s fast charging pad can output up to 30W of power, but it needs big and loud fans to dissipate all the generated heat.

    Also, to make your wireless charging experience more efficient, make sure you place your earbud’s charging case in the center of the charging pad, where the coil is located.

    USB Charging Standards

    We pretty much all have some sort of portable device that uses a USB port. There are many different USB standards, with newer ones being more capable of transferring electricity.

    • USB 1.0: this old standard can output the maximum of 5V and 0.5A, with a total of 2.5W.
    • USB 2.0: still a widespread standard, with the same maximum output as USB 1.0.
    • USB 3.0: one of the most common standards today with an output of 5V and 0.9A, and total power of 4.5W.
    • USB 3.1: this standard includes the USB-C, which can operate with USB-PD (USB Power Delivery). The result is the maximum output of 5-20V, 0.5-5A, with a total power of 100W.

    It’s important to know that the fastest charging speed can be achieved only with USB-C. Chargers with USB-A are not capable of power delivery beyond 18W.

    The charging case with USB-C and microUSB
    Jaybird Vista’s charging case (left) is able to quick-charge its buds, whereas TaoTronics’s case (right) can’t.

    Types of Fast Charging Standards

    USB Power Delivery

    This standard was developed by USB Implementers Forum, the creators of the USB standard. The USB Power Delivery is an open standard, meaning any manufacturer can implement it in their device, as long as they have USB-C port. At its maximum power, it supports fast-charging up to 100W.

    Smartphones and other smaller gadgets usually don’t get past the 50W mark, whereas some laptops (MacBook Pro) can charge at full 100 Watts.

    Apple Fast Charging

    They use the USB Power Delivery standard to charge up their mobile devices. This is great since the USB Power Delivery is a widely available standard. The only difference is that you have to find different cables (USB-C to Lightning) unless you have a MacBook Pro or iPad Pro (both have USB-C port).

    All of their new phones support Apple Fast Charging, but only Pro models come with included fast chargers. The maximum charging speed to power their portable devices (except MacBook Pro) is 29W.

    Unfortunately, the Apple Airpods Pro don’t support fast charging but you can use them with a Qi-certified charging mat.

    Qualcomm Quick Charge

    Because almost all portable devices use some sort of Qualcomm chip, this is one of the most widely spread standards. The current one is called Qualcomm Quick Charge 4+, and it only works via USB-C. The good news is that USB Power Delivery chargers also support QC 4+. At its maximum, it can deliver charging speeds up to 27W.

    The most interesting feature from Qualcomm camp is the INOV (Intelligent Negotiation for Optimum Voltage). This feature was first implemented in Qualcomm Quick Charge 3.0 and is also supported by QC 4+. INOV can monitor the power output, therefore charging your device with better efficiency. Thanks to this intelligent power management, it can sustain the power output without overheating.

    Samsung Adaptive Fast Charging

    This method of fast charging is exclusive to premium Galaxy devices. The last two iterations have boosted the charging speeds with support for USB-PD PPS (Programmable Power Supply) standard. Now it reaches anywhere from 25W to 45W of maximum power.

    The good news is that you don’t have to rely on Adaptive Fast Charge certified chargers since most Samsung devices support Quick Charge-compatible chargers.

    Samsung GalaxyBuds+ supports fast charging that gives 1 hour of music for a 3-minute charge. But it doesn’t support the adaptive version.

    Samsung Adaptive Charging charger
    Samsung’s “Adaptive Fast Charging” fast charger.

    Does Fast Charging Matter for Headphones?

    More and more manufacturers say their headphones support rapid charges, giving a few hours of playtime in just a couple of minutes.

    • For example, a 10-minute can give you around 2 hours of playtime, sometimes even more.

    When using true wireless earbuds, the quick charge happens inside the charging case, without needing to plug it into a wall. It’s a must-have feature for the best workout headphones that you might forget to charge before going to the gym.

    By contrast, other wireless earbuds and headphones quick charge by using wall chargers. How much power they can take is listed inside the manual or on the manufacturer’s website.

    Fast charging gives you a significant boost in battery life until it reaches 80% of the capacity.

    The Future of Fast Charging

    Charging is becoming faster each year, with more devices offering to refill their battery quickly. This trend is about to grow further, taking us just a few minutes to charge our portable gadgets fully. We can also expect to see different kinds of battery technologies that will replace the lithium-ion batteries of today.