The Xiaomi Mi Smart Band 4 fitness bracelet remains one of the most popular gadgets for monitoring activity even years after its release. Its compact design, long autonomy and rich functionality make the device an indispensable assistant in everyday life. However, many users face difficulties when first charging - an unobvious connector, lack of indication or fear of damaging contacts often cause errors.
In this article, we will discuss all the ways to charge the Mi Band 4, including the nuances of connecting to the charger, the time of full charging and typical problems (for example, when the bracelet does not respond to the connection to the network). How to avoid overheating, what to do when moisture enters the connector and how to extend the battery life. NFC Special editions (e.g. Avengers Edition).
Preparation for charging: what will be needed
Before you start charging, make sure you have everything you need. The Mi Band 4 comes with a proprietary charger (not compatible with other Xiaomi bracelet models!) that plugs into any device. USB-If the original cable is lost, you can use compatible analogues, but with caution - poor charging can damage the battery.
Here is a complete list of what you will need:
- 🔌 Original charger Xiaomi Mi Band 4 (model) M2004B1 or similar).
- 📱 power supply: USB-port of computer, laptop, charger for smartphone (5V/1A or 5V/2A) power bank.
- 🧼 Dry wipe or cotton swab to clean contacts (if necessary).
- ⏱ Timer (optional) – to track charging time.
If you use a non-original charger, check its parameters: the voltage should be strictly 5V, and the current strength should not exceed 2A. Exceeding these values can lead to overheating of the bracelet power controller and shorten the battery life. Also avoid cheap cables with thin wires - they can cause voltage drawdown and slow charging.
Step-by-step: how to connect the bracelet to charging
The charging process of the Mi Band 4 is different from the usual gadgets — there is no USB-C or Micro-USB connector. Instead, it uses a magnetic connector that is attached to the back of the case.
- Take the capsule off the bracelet. Carefully remove the main module (with a display) from the silicone strap, pulling it aside. Don't put too much effort - the locks are plastic and can break.
- Find the charging contacts. There are 4 metal contacts on the back of the capsule (two large ones on the sides and two small ones in the middle) that should match the contacts on the charger.
- Connect the charger. Attach the capsule to the magnetic connector of the charger, and it must stick on its own. Make sure that the contacts match perfectly: even a slight shift can lead to no charging.
- Put it on the power source. USB-charger cable to the port of the computer, adapter or power bank. on the screen of the bracelet should appear an animation of charging (battery with lightning).
The bracelet and charging contacts match visually |
Capsule "magnetized" to connector without backlash |
The bracelet screen displays the charging indicator |
The charger is connected to the power source 5V/1-2A-->
If the charging indicator does not appear after connecting, try the following steps:
- 🔄 Reconnect the capsule to charging, making sure the contacts match.
- 🔌 Try another one. USB-power-port.
- 🧹 Clean the contacts of the bracelet and charger with a dry wipe (without alcohol!).
- 🔋 Reboot the bracelet by holding the touch button for 10 seconds.
⚠️ Warning: Never use abrasive materials ( sandpaper, metal objects) or alcohol-based liquids to clean contacts. This can damage the protective coating and cause corrosion.
How long does Mi Band 4 charge: norms and deviations
The full charging time of the Xiaomi Mi Smart Band 4 depends on several factors: the current charge level, the quality of the charger and the power source. On average, the process takes 1.5-2 hours from 0% to 100%.
| Level of discharge | Charging time (original ROM) | Charging time (non-original ROM) |
|---|---|---|
| 0–20% | 1 hour 20 minutes - 1 hour 50 minutes | 1 hour 50 min - 2 hours 30 min |
| 20–50% | 40-60 minutes | 60-90 minutes |
| 50–80% | 20-30 minutes | 30-50 min |
| 80–100% | 10-20 minutes | 20-40 minutes |
If your bracelet is charged much longer than the specified norms, this may indicate:
- 🔋 Battery wear (if the device is more than 2-3 years old).
- 🔌 Use of a poor-quality charger.
- 📉 Contact problems (oxidation, pollution).
- 🔄 Firmware failure (solved by rebooting or resetting settings).
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To speed up charging, use an output power adapter 5V/2A instead USB-computer port (there is often a current restriction) 0.5A).
After reaching 100% charge, the bracelet automatically turns off power, but it is not recommended to leave it on charging for longer than 3-4 hours. Constant connection to the network can reduce the life of the lithium polymer battery. The optimal mode is to charge the device to 80-90% and turn off.
Typical errors and their solutions
Even with the right connection, users face charging problems, and let's look at the most common cases and how to fix them:
1.The bracelet does not respond to charging
If the charging indicator does not appear after connecting to the network, follow the following steps:
- 🔍 Check the integrity of the cable and charger contacts.
- 🔄 Try another one. USB-port.
- 🔋 Hold the touch button of the bracelet for 10-15 seconds for forced reboot.
- 🧹 Clean the bracelet contacts and charge with a dry toothbrush (soft!).
2. Slow charging
If the process is too long (more than 3 hours), the reasons may be as follows:
- 🔌 The power supply does not provide sufficient current (for example, USB-port-port).
- 🔋 Bracelet battery worn out (check the battery life - if it is reduced by 2)+ Once, it's time to change the battery).
- 📱 Background processes (e.g. synchronization with Mi Fit) can increase charging times.Switch off Bluetooth on your smartphone while charging.
3.The bracelet overheats during charging
Light heat is normal, but if the case gets hot (over 40°C), immediately disconnect it from the mains.
- 🔥 Faulty charger (use only the original charger!).
- 🔋 Battery bloating (requires replacement!).
- 🌡 Charging under direct sunlight or in a stuffy room.
⚠️ Warning: If the bracelet continues to warm or discharge rapidly after disconnection, this is a sign of critical wear of the battery.
What if the bracelet does not turn on after charging?
How to extend the battery life
The Mi Band 4 lithium-polymer battery is designed for 300-500 charging cycles, but if used improperly, this figure can be reduced by 2-3 times.
- 🔋 Avoid deep discharge (below 10%) and charge the bracelet at 20-30% charge.
- ⚡ Do not keep the device on charge for more than 3-4 hours after reaching 100%.
- 🌡 Avoid extreme temperatures: Do not charge at temperatures below 0°C or higher than 35°C.
- 📵 Turn off unnecessary features (such as call notifications if they are not critical) to reduce power consumption.
- 🔄 Once every 2-3 months, perform battery calibration: discharge the bracelet to 0% and charge to 100% without interruptions.
You should also pay attention to the energy saving mode in the Mi Fit settings. Activating it will increase autonomy by 20-30%, but you will lose some of the functions (for example, constant monitoring of heart rate).
- Open the Mi Fit app on your smartphone.
- Go to Profile → Mi Smart Band 4 → Additional settings.
- Activate the option Power Saving Mode.
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The optimal charge range for battery life is 20-80%, and constant charging to 100% and discharge to 0% reduce battery life by 30-40%.
Alternative charging methods (in case of loss of RMS)
If the original charger is lost or broken, alternative methods may be used, but remember: these are temporary solutions and frequent use of these can damage the bracelet.
1.Use of universal charging for fitness bracelets
There are universal chargers with adjustable contacts (for example, Baseus Universal Charger) on sale.
- The distance between the contacts is the same as the Mi Band 4 (18mm) between the external contacts.
- The voltage at the exit is exactly 5V.
- The polarity of the connection is correct (plus to plus, minus to minus).
2. Charging from another Xiaomi bracelet
The chargers from the Mi Band 5/6 are not physically suitable, but you can use the charger from the Mi Band 3 (model M2003B1) - the contacts are the same.
- 🔌 The charging current may vary, which will increase the process time.
- 🔋 Risk of damage to contacts with careless connection.
3. Homemade charger (extreme case!)
If there are no other options, you can temporarily use it. USB-cable with bare wires, but this requires care:
- Take any one. USB-cable and cut the connector Micro-USB/Type-C.
- Clean the red (+5V) and black (GND) wires.
- Attach them to the appropriate contacts of the bracelet (external contacts - plus and minus, internal - data, they can not be connected).
- Secure with tape or tape, making sure there is no short circuit.
⚠️ Warning: Homemade chargers can cause overheating, battery bloating, or power controller failure. Use this method only in emergency cases and do not leave the bracelet unattended!