You must have heard at least once about "Qi charging" already. This article will talk about this charging standard, why is it so popular, and why should we use it? In essence, Qi is the name of a standard for wireless power transmission technology. The format of this standard is proposed and validated by the Wireless Power Consortium (WPC). The initial goal is to standardize wireless charging for all electronic devices from many different hardware vendors, similar to the way USB or Bluetooth standardizes technology.
In terms of smartphones only, we currently have a lot of devices, each of which uses a separate charging standard like MicroUSB, USB C, or Lightning. These three common types can be considered as few, if there is no common standard, each company will use a different type of port, you can imagine how complicated it is. This is similar to wireless charging, so Qi was born. The more common you use, the better the user experience. Take USB C for example: currently only need one C, you can charge for MacBook, iPad, Android phones, etc., in the future may be new iPhone too. In fact, companies can still create their own standards, but that will take more time to develop, use more cumbersome and ineffective.
Going back to wireless charging: this technology works based on magnetic induction or magnetic resonance to transmit energy. To understand this technology, you can read the article Wireless charging and things you may not know. The Qi standard uses both magnetic induction and magnetic resonance for charging. This standard is designed to help users avoid three major problems:
- Power overload: each smartphone has a limited capacity to prevent incidents. As mentioned, wireless charging is highly dependent on wire cores, if not set a common standard, there is the possibility that an overcharged charger could damage a device that only supports low power charging.
- Overheating: same as above, using a more powerful charger than a supported device can make it too hot, worse than a fire. We have witnessed enough of these fires and know how dangerous it is.
- Disturbance: Due to the so-called Foreign Object Detection (FOD), roughly translating is the detection of a foreign object, a wireless charger can tell where it is actually the secondary wire core in the phone to transmit electricity and where it is a strange object. For example, a metal plate can be considered a coil. This is dangerous because it can cause heat, fire or explosion.
A charging device, or a phone attached to the Qi standard, is tested by WPD to ensure safety, efficiency and compatibility. The Qi standard will allow devices to operate within 0 to 30 Watt. In fact, the Qi supports up to 1 kW, but not for phones. The device must pass the temperature test, and work well with the FOD mechanism mentioned above. All Qi-based devices can be cross-linked, similar to the Micro-SD memory card that works with all MicroSD slots.
Qi standard focuses primarily on energy regulation. Wireless chargers using this standard take the form of a flat surface, as it helps to distribute energy more steadily and reasonably. Qi-compatible devices can adjust the device's charge and switch to standby mode when the device is full of batteries. These chargers only work when the devices they consume are placed on the top, and when no devices are available, they switch to standby mode, not activated to save power during the process.
The charging efficiency will be better when the device is "attached" to the charging pads via magnets. In addition, the Qi standard allows the device to be more intelligent in charge control, which can detect when a fully charged phone will stop "sending energy" to prevent damage. The limit of this standard is whether charging is fast or slow, optimized or not, depending on charging behavior, charging only one machine at a time is best.
Do you remember the charger plates that appeared around 2008, which are Powermat (PMA) charging plates. The current Samsung Galaxy phones (S8, S9 and S10) still support the PMA standard, of course parallel to the Qi standard. However many users complain that their S10 does not work with PMA chargers.
One of the other notable standards is AirFuel (formerly Rezence). This standard uses magnetic resonance technology to charge and it supports some older old devices that now no one is interested in, for example, iPhone 5s wireless charging
The future of Qi standard
Wireless charging will definitely grow more in the future, I believe. The development of wireless charging will force WPC to research and develop their Qi standard. Many people commented that our wireless power technology is only at the beginning, there is a lot of potential to grow ahead. Currently WPC is targeting wireless charging for household appliances and electrical tools.
In addition, for wireless charging to grow, the key point is convenience and efficiency. No one wants to buy charger if it doesn't charge much, but too much power. Wireless charging is not as efficient as charging, but if it is optimized for efficiency, it will be extremely handy. As mentioned, the current Qi standard supports up to 1kW, this number is extremely large and can be exploited to make an indoor charging system.
A note: Never buy a charger without a standard
A device that wants to be certified must go through several steps of thorough testing to ensure safety, so the price is often high. I see many friends who buy floating floating chargers to try it, I don't support it. Electricity is a very dangerous thing, so don't regret the money but buy things that have been carefully tested to protect your device and protect yourself.
Lê Phú Khương