Why are users looking for alternative ways to charge the Mi Band 4?
The Xiaomi Mi Band 4 fitness bracelet remains a popular gadget even years after its release — its reliability, functionality and price make the device relevant. However, many owners have a typical problem: the loss or breakage of the original charging cable. Unlike modern models (for example, the Mi Band 7 with magnetic charging), the fourth version requires accurate connection of contacts, and a standard USB-type A connector is not always compatible with modern adapters.
It is possible to buy a new charger, but it is not always convenient: delivery takes time, and in some regions original accessories are unreasonably expensive. Fortunately, there are proven ways to charge the Mi Band 4 without native cable - from the use of universal chargers to homemade adapters made of improvised materials.
In this article, we will discuss 5 working methods, including step-by-step instructions, connection schemes and compatibility table with other Xiaomi devices, and learn what errors most often lead to bracelet failure when alternative charging, and how to avoid them.
Method 1: Using charging from other Mi Band models
The safest and easiest method is to use the charging cable from other Xiaomi bracelet versions, but not all models are suitable: a key difference in the location and shape of the contacts, as well as in the power supply voltage.
| Charging model | Compatible with Mi Band 4 | Notes |
|---|---|---|
| Mi Band 3 | ✅ Yes. | Full compatibility in contact and voltage (5V/0.1A) can be used without adapters. |
| Mi Band 5/6 | ❌ No. | The shape of the connector has changed. It won't physically connect. |
| Mi Band 2 | ⚠️ Partially. | The contacts match, but the voltage may differ. |
| Amazfit Bip | ❌ No. | Another type of connector and power circuit. |
How to connect:
- Remove the bracelet capsule from the strap.
- Carefully combine the charging contacts of the Mi Band 3 with the connector on the back of the Mi Band 4 (they should fit tightly).
- Connect the cable to USB-port of the computer or voltage adapter 5V.
⚠️ Note: If charging from Mi Band 2, check the voltage with a multimeter. 5.2V use USB-hub.
💡
Before connecting, wipe the contacts of the bracelet with an alcohol napkin - oxidation can interfere with charging.
Method 2: Homemade adapter from USB-cable
If you have an old one on hand USB-cable (such as from a mouse or keyboard), it can be converted into a charger for the Mi Band 4. This method requires accuracy, but allows you to do without buying a new accessory.
Materials required:
- 🔌 USB-Type-A cable (you can use damaged cable if you have whole wires)
- 🔪 Stationery knife or cutter
- 🧲 Double-sided scotch or heat-glue
- 📏 Line (for precise marking)
Step-by-step:
- Cut the Type-A connector off the cable, leave ~10cm of wire.
- Clean the insulation by 5-7 mm, baring red (+5V) and black (GND) wires.
- Attach the bare ends to the bracelet contacts: Red wire to the right contact (when you look at the back of the capsule); black wire to the left contact.
Secure the wires with tape or heat glue, avoiding short circuit.
Connect. USB-power-storage.
Cleared wires do not touch each other | Polarity observed (red - right) | Power supply voltage does not exceed 5V| Bracelet removed from the strap-->
Critical: if you confuse polarity, the bracelet can fail. Before you first connect, check the voltage with a multimeter!
What to do if the bracelet is not charged?
Method 3: Charging through a power bank or other USB-device
If you have a power bank, a smartphone with a function OTG or even a game console (for example, Xiaomi Mi Box), they can be used as a power source for the Mi Band 4. USB-port 5V.
Suitable devices:
- 🔋 Power Bank (anywhere, with exit) 5V/1A or 5V/2A)
- 📱 Smartphone with support OTG (For example, the Redmi Note 10, POCO X3)
- 🖥️ Laptop or desktop (USB 2.0/3.0)
- 🎮 Gaming devices: Mi Box S, NVIDIA Shield TV
How to charge:
- Connect the bracelet to USB-port of the device via the original cable (if any) or homemade adapter (see Method 2).
- If you are using a smartphone with OTG, Enable the option of Reverse Charging (on the settings) MIUI Path: Settings → Additionally. → OTG-charging).
- Wait for the charging indicator to appear on the bracelet screen (battery icon).
⚠️ Warning: Some power bank shuts down when the power current is low (like the Mi Band 4). If charging is not working, try plugging the bracelet before power bank activation or use a 200-300 Ohm resistor between the two. +5V and GND load-stimulating.
💡
Smartphones with fast charging (for example, Xiaomi) 11T) They may not recognize the bracelet because of the low current. USB-hub 5V/0.5A.
Method 4: Wireless charging – myth or reality?
Many users are wondering if you can charge the Xiaomi Mi Band 4 via wireless charging (like the Xiaomi Mi 11 or Redmi Note 10 Pro smartphones). Unfortunately, the fourth version of the bracelet does not have a built-in Qi coil, so standard wireless chargers will not work.
But there's a workaround, which is to use a contact adapter to charge wirelessly.
- Buy a universal Qi-adapter with spring contacts (sold on AliExpress or in electronics stores).
- Attach the adapter contacts to the back of the bracelet (similar to Method 2).
- Place the adapter on the wireless charging pad.
This method works, but has disadvantages:
- ⚡ Low charging speed (due to double energy conversion).
- 💰 Additional costs for an adapter (~300-500 rubles).
- 🔥 Risk of overheating with prolonged use.
If you still decide on this method, choose heat-protected adapters and do not leave the bracelet on charging for more than 2 hours in a row.
Method 5: Charging from a solar panel or other alternative sources
In emergency situations (for example, on a hike), you can charge the Mi Band 4 from a portable solar panel or even from AA batteries.
- 🔋 Solar panel with USB-exit 5V).
- 🔌 Battery adapter AA on USB (sold in tourist shops).
- 🛠️ Wires and tape (if you assemble the circuit yourself).
Connection scheme from batteries:
- Build a chain of 4 AA batteries (total voltage ~6V).
- Connect via a diode (e.g., 1N4007) to stabilize the voltage to ~5V.
- Attach the wires to the bracelet contacts (observing polarity!).
⚠️ Warning: Battery voltage is unstable and may exceed 5V, This method is only used as a last resort and not longer than 30 minutes!
Any solar panel is suitable for USB-cable (see Method 2). The main thing is to make sure that the panel does not give more 5.2V. In cloudy weather, charging can go extremely slowly or interrupted.
Frequent Mistakes and How to Avoid Them
When alternative charging Xiaomi Mi Band 4 users often make mistakes that lead to damage to contacts, battery discharge or even breakage of the bracelet.
| Mistake. | Effects of consequences | How to avoid |
|---|---|---|
| Wrong polarity | Short circuit, failure of the power controller | Check with a multimeter or use marked wires |
| Use of adapters >5V | Battery overheating, bloating | Check the voltage before connecting. |
| Charging in the strap | Poor contact, slow charging | Always remove the capsule from the strap. |
| Long-term charge (>3 hours) | Battery degradation | Turn off after reaching 100% |
Another common problem is that the bracelet doesn't turn on after alternative charging, and there are many reasons:
- 🔋 Full battery discharge (you need to hold on charging for 15-20 minutes).
- 🔌 Oxidation of contacts (clean with alcohol).
- 💥 Power controller burned (requires repair).
If the bracelet does not respond to charging, try resetting it to factory settings: to do this, hold the touch button for 10 seconds until the Mi logo appears.