Xiaomi Mi 9 is one of the first flagships to be supported by Qi technology for power transmission at a distance. Device owners often wonder how to activate wireless charging, unaware that this process does not require complex manipulations in hidden menus. Unlike wired connection, where physical contact of the cable is necessary, it is important to properly position the gadget on the surface of the charging station.
However, despite the apparent simplicity, many users are faced with a situation where induction charging simply does not start, this may be due to software limitations, thick protective cases or features of MIUI. In this article, we will discuss in detail the algorithms for turning on, setting specific functions like "Mi Turbo Charge" for wireless mode and how to eliminate common errors.
Understanding the inductive coils will help you avoid the excitement of the wireless power transmission system in the Mi 9 is fully integrated into the operating system kernel, so there is no separate "Enable" button in the standard interface. Activation occurs automatically under a number of technical conditions, which we will discuss below.
Principles of operation and compatibility of chargers
To successfully run the technology in your Xiaomi Mi 9, you need a compatible charger that supports the Qi standard. The smartphone has a receiving coil that resonates with the transmitting coil of the base. If the base does not meet the minimum power requirements or communication protocols, the phone will simply ignore its presence.
It is important to consider that the Mi 9 supports fast wireless charging power up to 20 watts, but only when using the original accessory or certified analogues with support for proprietary Xiaomi protocols. In the case of using third-party Qi databases, the speed will be limited to the basic 5-10 watts, which will significantly increase the time of recharge of the battery.
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Use Xiaomi’s original charger with at least 27 watts of power to wire the base to ensure a maximum wireless power transfer rate of 20 watts.
Also worth noting is the impact of foreign objects: magnetic holding rings mounted on the back cover or metal plates can block the electromagnetic field, which will not only stop the process, but can also cause components to overheat.
- 🔋 Make sure the charging base supports Qi 1.2 or higher.
- 🔋 Check the specification of the power supply to which the base is connected (minimum) 18-27 Watt).
- 🔋 Remove cases with metal inserts or magnetic rings before installing the phone.
- 🔋 Center your smartphone so that the coils are opposite each other.
Activation and configuration algorithm in MIUI
As mentioned earlier, the auto-activation feature is built into the firmware of the device. You don't have to look for the switch in the settings. Just put the Xiaomi Mi 9 on the operating base. If all the conditions are met, the screen will light up and you will hear the characteristic sound signal, and also see the animation of the charging battery.
To get a deeper setup, go to the settings menu. Open Settings, then find the Battery section. This shows the current power status. If the device starts taking power, you'll see the indicator as a percentage and the time to fully charge. Some versions of MIUI firmware may display the Optimized Night Charge switch here.
☑️ Verification of activation of wireless charging
The Mi Turbo Charge features are particularly important when wirelessly activated automatically when using compatible hardware, at which point the system can limit the background activity of the applications and the brightness of the screen to reduce heat generation, which is a normal reaction of the software to high currents.
If you plug in your phone but it's not charging, try unlocking the screen. Sometimes the security system requires you to confirm the owner before you start taking power, especially if the phone has been completely turned off or discharged to zero.
Optimization and management of temperature regime
The inductive way of transferring power inevitably involves the generation of heat. The Xiaomi Mi 9 has a complex thermoregulation system that can force the charge current to decrease or suspend it if the battery temperature exceeds a safe threshold.
To minimize heat and speed up the process, it is recommended to remove dense silicone or leather cases during the procedure. The thick layer of material creates an air cushion that prevents heat from being removed from the back cover of the smartphone to the surface of the charging pad.
⚠️ Warning: Do not cover your smartphone while wirelessly charging with cloth or other items, which will result in critical overheating and possible damage to the battery or internal electronics.
MIUI can also limit background processes, and if you notice your phone is warmer than usual, close heavy applications like navigation or gaming before installing it on base, and keep the heat low in standby mode.
Why does the charging stop at 80-90%?
Speed comparison and efficiency of methods
It is important for users to understand the difference between wired and wireless connections. Despite marketing claims of 20 watts "over the air", the real numbers are often lower due to the energy loss during the conversion of the electromagnetic field.
Below is a table showing the approximate time costs for Xiaomi Mi 9 with a 3300mAh battery using different methods.
| Charging method | Maximum power | Time 0-50% | Time 0-100% |
|---|---|---|---|
| Wire (27 W) | 27 Watts | ~30 minutes | ~65 minutes |
| Wireless (Original) | 20 W. | ~45 minutes | ~100 minutes |
| Wireless (Qi Standard) | 5-10 W. | ~60+ min | ~140+ min |
As you can see from the data, the wireless method loses in speed by about 1.5-2 times, but the ease of use "on the go" or at night compensates for this disadvantage. For fast charging during the day, it is still preferable to use a USB Type-C cable.
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Wireless charging is ideal for night use or office desks, but for an emergency power set, it’s quicker to use the cable.
Diagnostics of problems and troubleshooting
If your Xiaomi Mi 9 has stopped responding to the charger, the first thing you do is check the base itself. Connect another Qi-enabled device to it. If it doesn't charge, the problem is the power supply or the station itself. If the other device is working, it's the smartphone.
A common cause of failure is a software glitch of the power controller, in which case a banal system reboot helps, and it is also worth checking the USB-C connector for dust, since some base models may try to transmit data or current through the port if it is contaminated, although this is rare for purely inductive models.
- 🛠 Check if the indicator is on the charging base itself.
- 🛠 Clean the back cover of the smartphone and the base surface from dust and grease.
- 🛠 Try to move your phone a couple of millimeters in either direction.
- 🛠 Reboot the device if the problem occurs suddenly.
In rare cases, a network reset or battery calibration may be required, but this is usually only required after major firmware updates or battery replacement at a service center.
The effect of accessories on the efficiency of transmission
The choice of protective cover is critical. Thin polyurethane or plastic linings up to 2-3 mm thick usually do not interfere with the operation of the coil. However, any thickening, relief patterns or inserts of carbon fiber can increase the distance between the coils beyond the permissible.
The critical distance between the transmitter and receiver coil in Xiaomi Mi 9 is a gap of 4-5 mm. Exceeding this value leads to a sharp drop in efficiency and an increase in temperature, which causes the controller to interrupt charging.
Magnetic rings for car holders should be glued strictly in the center if you plan to use wireless charging, or remove them. Metal shields the field, and the phone can even heat up without getting any percentage of power.
⚠️ Note: Magnetic stripe cards or RFID-chips (travel, hotel keys) left between the phone and charging can demagnetize or burn due to induction currents.