Wireless charging for Xiaomi with your own hands: from circuit to working device

Wireless charging has long ceased to be exotic – even budget Xiaomi smartphones (for example, Redmi Note 12 Pro)+ or POCO X5 Pros support Qi out of the box, but what if your model (say Redmi 9 or Mi) is a good model? 10T) Can't charge without a wire, and you don't want to buy an original adapter.

In this article, we will discuss three working ways to create wireless charging for Xiaomi: from a simple circuit based on ready-made modules to a homemade coil with a resonance adjustment. You will learn what materials you will need, as avoidable errors (for example, overheating or low current), and why some smartphones refuse to charge from homemade devices.

Before you start, check if your Xiaomi supports the Qi standard.

1. Open Settings → About the phone → Full specs.
2. Find the line "Wireless charging".
3. If it is not, your model is not compatible out of the box, but it is not a sentence!

Even if the smartphone does not support Qi, it can be modified with a special receiver module (more about this in the last section).

1. Methods of creating wireless charging: which one to choose?

All homemade charging is divided into three types in terms of complexity and efficiency:

• 🔌 Finished module + The power supply is the easiest option. It's good for beginners: just build a circuit from the top of the box. 3-4 The power of the detail: 5–10 Waht (enough for Redmi Note) 11 or POCO X4 Pro).
• 🔄 Homemade coil + Driver - requires soldering and tuning skills, allows you to achieve power up to 15 watts (suitable for the Mi 11 Ultra), but the risk of overheating is higher.
• 🛠️ Resonance charging is a challenging project for enthusiasts, giving freedom in design (you can build it into a desk or car console), but requires accurate calculations and testing.

If you want fast and reliable charging for your home, take a module ready (for example, a module that is fast and reliable, XL6009 + If you want to experiment with power and design, try a homemade coil. Resonance circuits are left for later: they are capricious in setting up and often conflict with the protection of Xiaomi smartphones.

⚠️ Note: Xiaomi Qi-enabled smartphones (such as the Mi 13 Pro or Mix Fold 3) can block homemade charging if not certified. This is not a fault, this is how overheating works. Solution: Use current stabilization circuits (more on this below).

Before you buy the details, answer two questions:

1. What charging current supports your smartphone? (You can find out in the manual or on the Mi Community website.)
2. Where will the charging be used? (home desk, car, backpack - the choice of the case depends on this.)

Materials and tools: full checklist

Depending on the method you choose, you will need different components, and below is a universal charging assembly kit based on the finished module (the most popular option).

Transmitter board (e.g. Qi Transmitter) V2.0)

Power supply 5V/2A (It will fit the charger from Xiaomi 20W)

Receiver coil (if the phone does not support Qi)

Condensers 100nF and 1uF (stabilizing)

Wires, solder, flux.

The body (you can use an old case or 3D-seal)

Multimeter for voltage testing

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Where to buy it?

• 🛒 AliExpress – cheap modules (for example, Qi Wireless Charging Module for 3-5)$), but delivery 2-4 weeks.
• 🏬 Local radio shops are faster but more expensive (the module will cost 800-1500). ₽).
• 🔧 Older devices – coils can be soldered out of broken wireless charges or mice.

Important: If your Xiaomi does not support Qi, additionally buy a receiver module (for example, Qi Receiver for Qi Receiver). Micro-USB/Type-C). It plugs into the phone's connector and allows you to charge wirelessly: 2–4$ AliExpress.

⚠️ Note: Do not use power supplies higher than 2And for homemade circuits! Xiaomi can block charging because of excess current — 5V/2A (standard USB-charging).

3. Scheme and assembly: step-by-step instructions

Consider the most reliable option – the charging assembly based on the Qi Transmitter module V2.0. This scheme works with most Xiaomi smartphones, including the Redmi Note 10 Pro, POCO F3 Mi 11 Lite.

Step 1: Preparation of the module

1. Take the Qi Transmitter fee and solder to your contacts VIN+ and VIN- Power supply (observe polarity!).
2. Contacts. TX+ and TX- If the coil is homemade, use an enameled wire 0.5-1 mm in diameter wound in 10-15 turns.
3. Add capacitors: 100nF feeding-on, 1uF — between TX+ and TX-.

Step 2. Set up the coil

• 🔍 The distance between the turns should be uniform - otherwise the field will be unstable.
• 📏 Optimal diameter of the coil: 50–60 mm (suitable for most smartphones).
• 🔥 After soldering, check the resistance of the coil with a multimeter - it should be within 0.5-2 ohms.

Step 3. Testing

1. Connect the power supply and put on the coil smartphone with support for Qi (or with a receiving module).
2. If charging doesn't start: Check the polarity of the coil connection. Make sure the distance between the phone and the coil is no more than 5-8 mm. Try another power supply (sometimes Xiaomi "capricious" with cheap charging).

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If the smartphone starts charging, but after 10-20 seconds it stops, the problem is overheating. Solution: add a radiator to the chip of the module or reduce the current to 1A.

Step 4: Body and final assembly

For the housing, the following may be used:

• 📱 Old Case by Xiaomi (cut the hole for the coil).
• 🖨️ 3D-Print (find the finished model on Thingiverse on request "Qi charger case").
• 📦 Plastic box from the electronics store.

The critical detail: if you use a metal case, the charging won't work! The metal shields the electromagnetic field.

4.Why isn't Xiaomi charging from homemade charging?

Even if you put it together correctly, your smartphone can ignore charging.-5 causes and solutions:

1. No Qi support → Buy a receiving module (see Section 2).
2. Weak current. → Check the power supply (should be at least 2A) and the quality of soldering.
3. Incompatible frequency → Some modules run at 110-205 kHz, and Xiaomi expects 140-150 kHz. Solution: Replace the capacitors on the coil.
4. Overheating → Add a radiator or fan (for powerful circuits) >10 Watts).
5. Protection MIUI → Xiaomi firmware sometimes blocks uncertified charges.Solution: disable battery optimization in Settings → Battery → Performance mode.

If the phone starts charging but stops after a few seconds, the problem is the unstable current.

• Quality of the ration (especially on the coil).
• The voltage at the output of the power supply unit (should be exactly 5V).
• No foreign metal objects near the coil.

5. Increased power: how to make charging faster?

Standard home-made charging is 5 to 7 watts, enough for overnight charging, but not enough for quick battery recovery, to increase power to 10 to 15 watts (like Xiaomi’s). 30W Wireless Charger, you need it:

1. Replace the power supply by 9V/2A (For example, from a MacBook or Xiaomi 33W).
2. Use a two-coil circuit (transmitting) + resonant-condenser).
3. Add a current controller (for example, TP4056 stabilizing).

Warning: Increased power leads to:

• ⚡ Overheating (requires a radiator or active cooling).
• 🔋 Fast battery wear (especially on older Xiaomi smartphones).
• ⚠️ Short-circuit risk (if capacitors are not calculated correctly).

For experiments with high power, it is better to use ready-made solutions, for example:

• Module Qi 15W Transmitter (stands) ~15$ AliExpress).
• Payment XL6009 maximize 9V.

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Most Xiaomi smartphones (except flagships like the Mi 13 Ultra) do not support fast wireless charging. >10 watts. Even if you build a powerful circuit, the phone will limit the current to 7-8 watts.

6. Alternative ideas: non-standard solutions

If classic Qi-based charging isn’t right for you, consider these options:

• 🚗 Car Wireless Charging: Use the Qi Car Wireless Charger module (available on AliExpress for 10–15)$). Connect to the lighter through USB-- Hold it in the vent or on the torpedo.
• 🪑 Charging in furniture: Insert a module into a table or nightstand (example: 3D-model IKEA). Use a thick coil (20)+ turns) to increase range.
• 🔋 Power Bank with Qi: Buy a wireless charging battery (e.g. Xiaomi Mi Power Bank 3) 20000mAh). Disassemble it and use the module for homemade charging.

For Xiaomi with back-charging support (e.g. Mi 11 Ultra or Redmi Note 12 Pro)+) You can build a universal station:

1. Connect the transmission module to the Power Bank.
2. Add a second module to receive power (so that the phone can both charge and give off charge).
3. Use the switch to select the mode.

This device will allow, for example, to charge Xiaomi Watch S1 Buddy Bracelet from a smartphone without wires.

7.Security: How not to burn your phone?

Homemade charging is always a risk, so you can avoid problems.

• 🔥 Do not exceed 10 watts of power without active cooling.
• 🛡️ Use a safety lock on 1-2A in the supply chain.
• 📉 Control the temperature – if the body is heated above 40°C, turn off the charging.
• 🔌 Do not leave unattended overnight (risk of fire in case of poor ration).

Typical Beginner Mistakes:

1. Use of Chinese power supplies without certification (can give power surges).
2. The soldering is thick soldering, which creates cold contacts.
3. Ignoring polarity when connecting the coil (will result in no charging).
4. Placement of metal objects next to the coil (shields the field).

⚠️ Attention: If after connecting homemade charging, the Xiaomi smartphone begins to warm up strongly or discharge quickly - immediately turn it off! This is a sign of voltage incompatibility or short circuit.

For additional protection, you can add to the scheme:

• Schottky's diode, for example, 1N5822) back-current.
• Thermistor (for automatic shutdown in case of overheating).
• LED-indicator (shows if the charge is going on).

8. Phone upgrade: how to add Qi support?

If your Xiaomi doesn’t support wireless charging, there are two ways to fix it:

Method 1. Receiving module (the simplest)

1. Buy Qi Receiver for your connector (Micro-USB, Type-C or Lightning for your connector) POCO M3).
2. Insert the module into the phone and put it on the charging pad.
3. Secure the module with scotch or 3D-slack.

Method 2: Built-in receiver (more complex but more reliable)

This will require:

• Disassemble the phone (risk of losing the warranty!).
• Sell the Qi receiver directly to the battery contacts.
• Fix the coil under the back cover (need to cut the recess).

Advantages of the built-in solution:

• ✅ No wires sticking out.
• ✅ Any Qi charger can be used (including car charging).
• ✅ Less energy loss (efficiency 10-15 higher%).

What Xiaomi models can be improved?

⚠️ Note: With built-in revision, Xiaomi can block charging if the coil is located too close to the antennas NFC or 5G. Before assembly, check the location of components on the circuit (iFixit or Mi Community).

FAQ: Answers to Frequent Questions