Since Apple introduced its new iPhone last fall, wireless charging technology has been in the limelight ever since. Wireless charging is a new technology allows charging without cable over a short distance. Wireless charging has many advantages; it is not only quicker and more comfortable compared to traditional charging method; some quick wireless charging pads even allow you to charge multiple devices in one go, which your life so much easier.
If you are not familiar with wireless charging technology, I’m going to get started with the necessary information. Qi is an open interface standard that defines wireless power transfer using inductive charging, and the technology can be leveraged up to a distance of cm. Qi standard was developed by the Wireless Power Consortium (WPC) in 2010. One thing you need to know about the Qi standard is, it features both inductive and resonant charging.
Inductive charging is a method of Charging, where there is no need to plug the battery of Smartphones directly into a power socket. When the distance between receiver and transmitter become more prominent, the magnetic coupling between the coils also drops; in this case, systems with a low coupling factor must be operated at a resonant frequency of the receiver, and this is called resonate charging.
Most popular devices which support Qi charging are listed as below.
Samsung Galaxy S9 / Galaxy S9+/ Galaxy Note 8/ Galaxy Note 5/ Galaxy S8/Samsung Galaxy S8+/ Galaxy S8 Active/ Galaxy S7/ Galaxy S7 edge/ Galaxy S7 Active
LG G6/LG V30 series LG: V30, G6 (US version only), G4 (optional), G3 (optional)
Moto Z series (with Mod)
Sony Xperia XZ2 *
Nokia 8 Sirocco
iPhone 8, 8 Plus, X
Microsoft Lumia: 1520, 1020, 930, 929, 928, 920
Google Nexus: 4, 5, 6, 7 (2013)
What is 5W and. 7.5W charging
When iPhone 8 launched last year, it initially supported only 5-watt charging; and the Company also recommended some authorized third-party accessories including Spigen wireless quick charger, Mophie, Belkin. However, since the iOS 11.2 has been updated, it also supports 7.5 watts for faster charging. In fact, there is no massive difference in speed between 5W vs 7.5W charging.
There are currently only two ‘Apple-approved’ 7.5-watt charging pads on the market; they are Mophie's wireless charging base and Belkin's Boost Up. And according to some informers, Apple has opened up its requirements to all partners, so more and more manufacturers will launch chargers that feature 7.5-watt charging with iPhones. And other well-known charging accessories brand such as Anker, Aukey are also getting their hands on quick wireless charging.
WPC vs PMA
The Wireless Power Consortium is established in 2010 with the support of over 300 leading companies; these companies represent the leading industries including semiconductors, magnetic, wireless operators, mobile and consumer electronics. Some of you may have already known that the competing wireless power standard of WPC is Power Matters Alliance (PMA). The mission of PMA is to standardize and advance a suite of interface standards for the smart and highly efficient transfer of wireless power. The PMA has been working on the standard based on inductive coupling technology to provide high performance inductive and resonant power.
The real differences between PMA and Qi are the connection protocols and transmission frequencies to communicate with control power management and devices. Resonant operates over a more extended transfer distance by changing the frequency of the oscillation to match between the receiver and transmitter precisely. The primary benefit of a resonance design is that power can be transferred to devices no matter the orientation in the magnetic field from a single transmitter coil. It’s worth noting that Powermat is one of the founding members of the PMA which combined with A4WP to create AirFuel.
Wireless Quick Charge
The latest Wireless Quick Charge, aka Qualcomm Quick Charge technology, is designed to deliver lightning-quick charging in phones and smart devices that operated on Snapdragon mobile platforms and processors. This technology significantly decreases the amount of time you spend tethered to an outlet. Users can realise the quick charge technology via a Quick Charge certified power adapter, including Type-C, to refill the battery of their devices operated on Snapdragon platform.
Quick Charge 4+ offers is the speed of convenience. For instance, if you are charging an accessory, such as a pair of Mpow headphones or a power bank which doesn't support either of the USB-A fast charging specs, the charging will maintain at either 500mA or 900mA.
|QC 2.0||5V, 9V, 12V, 20V||USB-A||2A|
|USB BC 1.2||5V||USB-A||15A|
|USB PD||Variable up to 20V||USB-C||4.6A|
|USB Type-C 3A||5V||USB-C||3.0A|
|USB Type-C 1.5A||5V||USB-C||1.5A|
|QC 4.0 (USB-PD Compatible)||Variable up to 20V||USB-C||4.6A|
|QC 3.0||Variable up to 20V||USB-A/USB-C||4.6A|
The majority of portable power banks on the market have both USB-C and multiple USB-A ports. Some of them have USB-A ports which can deliver the same voltage. Therefore, users have to make sure they plug the device into the battery port which can charge it the fastest rate if they want to juice the battery as quickly as possible.
USB Power Delivery
USB Power Delivery (USB PD) is a pretty new fast charge standard which was introduced by the USB Implementers Forum, the creators of the USB standard.This is an industry-standard open specification that offers high-speed charging with different voltage up to 20V.
USB Power Delivery is a rechargeable technology that uses the USB-C line cables and interfaces to transfer higher wattage to your device. This technique has two benefits: first, it is faster to charge, and second, it can provide more power for larger devices.
Let’s take a look at the differences between USB Power Delivery and Quick Charge.
|Quick Charge||USB Power Delivery|
|Maximum Power (Watt)||60 watt||100 watt|
|Compatible Device||Snapdragon Device||All devices|
|Interface||USB-C/Type A||USB Power Delivery is designed for Type-C|
In next article, we are going to talk about USB-C related products, stay tuned!