What is Qi protocol?

Qi protocol is a wireless charging standard introduced by WPC. It is similar to the QC of Qualcomm. The QC protocol of Qualcomm tells the charger what Protocol I need by applying a certain voltage after listening to the data angle in the data line on the mobile phone. The same is true for Qi protocol.

When your mobile phone is put on, the transmitter and receiver of the charger establish a connection, and then transmit a specific frequency to the mobile phone. The mobile phone will feed back the power I need The charger then emits the corresponding electromagnetic wave to charge the phone. Charging process is as follows: wireless charging adopts feedback debugging method, similar to RFID charging, which can be broken down into four steps like this:

1. The mobile phone is placed on the charging board.
2. The charging board detects an object according to the capacitance change of the sending measuring coil.
3. The configuration message received by the charging board adjusts the corresponding parameters of the coil and adjusts the oscillation frequency of the coil to start sending normal power.
4. The charging board also receives messages such as chargestatus and controlerror sent by the mobile phone. For example, if the mobile phone is full, it will send a message to the charger to tell him that I am full.

Why is Qi standard introduced?

When Samsung and Apple launched their own wireless charging mobile phones, they used their own private agreements. As a result, Samsung's wireless chargers could not help apple and other mobile phones to charge wirelessly. Even if they could, the charging efficiency was relatively low. In order to charge quickly, consumers need to buy official chargers. To put it simply, Samsung's agreement You can think of it as Korean, while Apple's agreement is in Chinese. When Samsung wants to charge, it sends a sentence to the charger: smecta, and then the charger feeds back a sentence of smecta, and then it can be quickly charged. Put on the Apple phone, apple sends a sentence to the charger, Hello, the charger naturally can't be identified. So, as mentioned above, when the protocol fails to match, there is no way to charge normally.

In recent years, wireless charging has started to catch fire, and various private agreements are blooming everywhere. This leads to a phenomenon that you can't use a charger all over the world. Qi protocol is like English, which is universal in the world. After Qi certification, everyone can charge each other, saving money to buy chargers.

What are the Qi protocols

There are two kinds of Qi protocols: BPP EPP and Samsung private protocol Qi pdde. BPP can be understood as QC 2.0, EPP as 3.0, BPP (basic power profile) can be charged for 5W. With the demand for speed, 5W is far from enough. In terms of 5W demand, EPP (extended power profile) can support up to 10W charging. At present, the highest Qi protocol is epp15w. Of course, these all need the support of charger and mobile phone. And we can check the official website of WPC wireless alliance below to find out what protocols your phone supports.

Website address:https://www.wirelesspowerconsortium.com/products

Take millet 9pro 5g as an example

What to know from WPC wireless alliance's the official website

Through the official website query, you can know the product name, product type, mobile phone, etc. charging is the receiver, and then the registration time. However, these are not very important but pay more attention to the second line in the box is the version and the penultimate line. The penultimate line is the protocol, which determines whether you are BPP or EPP. The last line thinks that Qi protocol is the highest W. But Xiaomi 9pro supports 30W Ah, why is the above 10W? Again, check the site to figure it out.

Through the query, we can know that Xiaomi 9pro has passed the EPP 10W certification, that is to say, other Qi protocol EPP can help Xiaomi 9p 10W to charge, while Xiaomi's 30W is a private agreement, which can only be achieved by the official. In addition, the charger detects foreign matters through the Qi protocol. When a foreign object is placed on the charger, the charger sends a specific frequency to the foreign body. If there is no signal return, the power will be cut off.

To sum up, only by understanding the various charging protocols clearly can we be more smart when buying wireless chargers.