Buying an external battery from Xiaomi Power Bank is a big deal, especially when it comes to high-capacity models (20,000 mAh, 30,000 mAh) or fast-charging support. Xiaomi brand fakes are common in the market, and even original devices lose capacity or fail over time. How do you make sure you don’t overpay for a fake or worn-out battery? In this guide, we’ll look at 7 ways to check, from visual inspection to multimeter testing and specialized applications.
This article will be useful for those who are just going to buy Power Bank (for example, Mi Power Bank 3 Pro, Redmi Power Bank or Xiaomi Ultra Compact) and owners who want to assess the current state of their device. We will not limit ourselves to superficial tips like “look at the packaging” – here you will find specific tests, including checking the charge controller, measuring real capacity and diagnosing USB-C/USB-A ports.
⚠️ Important: Some methods require disassembling the device or using electrical measuring devices. If you are not sure of your skills, you should contact a service center!
1. Visual verification: how to distinguish the original from a fake
The first stage is external inspection. Counterfeiting often poses as a poor build, but some fakes copy the design almost perfectly.
- 🔍 Logo and inscriptions: On the original Xiaomi Power Bank, the Mi or Redmi logo is clear, without blurring, "18W Fast Charging is made with laser engraving, not paint, which is erased over time.
- 📦 Package: The box must be made of dense cardboard with high-quality printing, the original always indicates Made in China (not "Assembled in China"), and there is also a hologram with a serial number.
- 🔌 Ports and connectors: In models with USB-C (For example, Mi Power Bank 3 Pro, the connector must be symmetrical, without backlash. Counterfeiters often use cheap connectors with poor contact.
- 💡 Indicators: The LEDs on the original burn smoothly, without flickering. In fakes, they can flash chaoticly or display the wrong level of charge.
Pay special attention to the serial number (usually on a sticker under the case or on the package), it can be checked on the official Xiaomi website through the Mi Verify service, if the number does not pass verification, you are 100% fake.
⚠️ Warning: Some sellers stick stick stickers with serial numbers from the original Power Bank over fake devices. Always check the number on the box and on the battery itself.
2. Capacity check: real vs claimed
Manufacturers often overstate capacity in performance. For example, Xiaomi Mi Power Bank 3 Pro is billed as 20,000 mAh, but the actual available capacity is usually 10-15% less due to voltage conversion losses.
- 📱 Smartphone with support OTG (tablet).
- 🔌 Cable USB-C/USB-A (Depending on the Power Bank model).
- 📊 Charge measurement app, such as AccuBattery (Android) or Battery Life (iOS).
Step-by-step:
- Deplete the Power Bank (indicators must go out).
- Connect it to the charger and wait for 100% charge.
- Disconnect from the network and connect to the smartphone through the monitoring app.
- Discharge the Power Bank to zero, fixing how much mAh he gave.
Compare the result with the declared capacity, for example, if Redmi Power Bank 20000mAh gave only 12,000 mAh, that is a reason for a return under warranty, normal losses up to 20% (due to the efficiency of the converter).
Completely drain the Power Bank
Charge up to 100% of the original RAM
Connect to a smartphone with AccuBattery
Discharge to zero and record data
Compare with the declared capacity (tolerance of -20%)
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💡 Tip: Repeat the test 2-3 times for accuracy. The capacity may vary slightly due to ambient temperature.
3. Port and charging speed testing
Faulty ports are a common problem with both counterfeits and old original Power Banks, and can be checked without special equipment:
- 🔌 USB-A Ports: Connect your smartphone and check if it's charging. Original models support Quick Charge 3.0 (18W) or Power Delivery (up to) 45W Mi Power Bank 3 Pro).
- 🔌 USB-C port: Must operate in both directions (Power Bank charging and power output). PD (For example, Xiaomi Ultra Compact. 10000mAh) port USB-C can give up 22.5W.
To check the charging speed:
- Connect Power Bank to a smartphone with fast charging support (e.g. Xiaomi 13 Pro or Redmi Note 12 Pro+).
- Use the Ampere (Android) or ChargeSpeed (iOS) app to measure current.
- Comparison with the claimed characteristics: Model Power BankMax. power output Supported Mi Power Bank 3 Pro 20000mAh45WUSB-C PD, Quick Charge 3.0 Redmi Power Bank 20000mAh18WQuick Charge 3.0 Xiaomi Ultra Compact 10000mAh22.5WUSB-C PD
If the actual power is lower by 30% or more, the port is faulty or the charge controller is not working properly.
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If Power Bank is warming up while charging a smartphone, that's normal for fast-charging models, but if the case gets hot (over 50°C), turn it off immediately!
4. Check of charge and protection controller
The controller is responsible for safety: it prevents overcharging, short circuits and overheating. Counterfeiters often save on this part, which leads to a fire or explosion of the battery.
- 🔋 Recharge test: Leave Power Bank on charge after reaching 100%.The original device will shut down automatically after 1-2 hours.The fake can continue to charge, which is dangerous.
- ⚡ Short circuit test: Don't do this at home! Service centers check the controller's response to KZ with special equipment.
- 🌡️ Overheating test: Put the Power Bank in a warm place (like next to the battery) the original will shut down at temperatures above 60°C.
⚠️ Warning: If your Power Bank continues to charge after being disconnected from the network (indicators are on), stop using immediately.
What happens if you use a Power Bank with a faulty controller?
5. Disassembly and visual inspection of the board (for advanced)
If you're confident in your skills, you can open the body and look at the insides.
- 🔧 Plastic spatula or mediator (so as not to scratch the body).
- 🔨 Cross screwdriver (for some models).
- 🔍 Loop for microchip inspection.
What to check inside:
- 🔋 Battery elements: In the original Xiaomi Power Bank used cells from the LG, Samsung SDI or ATL. They must be marked with a date of manufacture, and counterfeits often contain cheap Chinese elements without insignia.
- 📱 Controller's fee: Originally, it's neat, it's soldered with a clear ration, and fakes may have solder stains or no protective diodes.
- 🔌 Ports and wires: All contacts must be soldered, without breaks. USB-C check for the chip. PD-controller (e.g., controller, CYPD3177 or similar).
⚠️ Warning: Disassembly voids warranty! If your Power Bank is still under warranty, it is better to contact Xiaomi service center.
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The most common reason for Power Bank failure is the battery cells bloating, and if the case is deformed or shows signs of "bloating", the device should be disposed of!
6. multimeter check (for accurate diagnosis)
The multimeter will help measure voltage and current to identify problems with the controller or battery. You will need: a multimeter with DCV and current measurement modes (DCA).
Voltage measurement:
- Transfer the multimeter to DCV 20V mode.
- Connect the black probe to the GND (minus), red to the V+ (plus) on the board or in the USB-A port.
- The original Power Bank voltage should be between 4.8 and 5.2V (for USB-A) or 3.6-4.4V (directly from the battery).
Current measurement: (Dangerous! Only do it if you are confident in your actions!)
- Transfer the multimeter to DCA 10A mode.
- Connect the Power Bank to the multimeter in series with the load (for example, a light bulb on the 5V).
- The current must be as stated (e.g. 3A for 18W charging).
⚠️ Note: Do not connect the multimeter in mode DCA Directly to Power Bank without load – this will lead to a short circuit!
7. Software diagnostics (for models with Bluetooth)
Some new Xiaomi Power Bank models (such as the Mi Smart Power Bank) support Bluetooth connectivity and have their own monitoring app to check the status of:
- Download the official Mi Power Bank app (available for Android and iOS).
- Turn on Bluetooth on your smartphone and connect to Power Bank.
- The annex will be displayed: 📊 Current capacity (in percent and mAh). 🔋 Battery condition (wear and tear, number of charging cycles). ⚡ Temperature and voltage.
If the app shows errors (e.g., Battery Health: Poor), the battery is worn out and needs to be replaced.