How to properly charge the fitness bracelet Xiaomi Mi Band 4: instructions with photos and tips

The Xiaomi Mi Band 4 fitness bracelet remains one of the most popular wearables due to its combination of functionality and affordable price, but many users are faced with questions about charging it: how to connect the cable correctly, how long it takes, and why the bracelet sometimes does not respond to the charger. In this article, we will examine all the nuances from choosing the original cable to solving typical problems.

It’s important to understand that improper charging can shorten battery life or even make the bracelet fail. For example, using unoriginal cables with improper voltage or interrupting the charging process halfway through often leads to device failures. We’ve put together proven guidelines to help avoid these errors and maximize the life of your Mi Band 4.

If you have just purchased a bracelet or are having trouble charging, this guide will be your guide, and for experienced users, we have prepared unique tips for optimizing the charging process and diagnosing faults that are rarely found in standard manuals.

What is the best charger for the Mi Band 4?

The original Xiaomi Mi Band 4 package includes a special magnetic connector charging cable, which has two key features:

• 🔌 Magnetic fastening – securely fixes the bracelet during charging and automatically turns off when a sufficient level of charge.
• 🔋 USB-Type-A connector – suitable for connecting to a computer, power bank or network adapter with output 5V/1A.
• ⚡ Charging current – the original cable supports current up to 500 mA, which ensures a safe and fast process.

Many users try to use cables from other Mi Band models (such as Mi Band 3 or Mi Band 5), but this is fraught with problems, because the connectors are visually similar but have different polarity of contacts.

• ❌ Bracelet failure to turn on.
• ❌ Battery overheating.
• ❌ Loss of warranty (if the device fails).

If the original cable is lost, we recommend buying a certified analogue marked MD-Y01 (original cable article). Such cables are sold in official Xiaomi stores or from trusted suppliers (for example, on AliExpress with a seller's rating above 98%). The cost of the original cable is about 300-500 rubles, while cheap counterfeits (from 100 rubles) often fail after 2-3 months.

⚠️ Warning: Do not use metal clamping cables instead of magnetic mounting.They can damage the bracelet contacts and cause short circuits.

Step-by-step: how to connect Mi Band 4 to charging

The process of charging the bracelet is simple, but requires care. Follow this instruction to avoid errors:

1. Remove the capsule from the strap. Find a small notch on the back of the bracelet. Carefully pull the capsule in the direction of the arrow (it is indicated on the body). Don't make excessive efforts - the mount must respond without creaking.
2. Connect the magnetic cable. The contacts on the capsule should match the contacts on the cable. The correct position is when the Mi logo on the bracelet is on top.
3. Connect the cable to the power source. USB-port of the computer, network adapter (5V/1A) Or power bank. Avoid higher-current adapters. 2A — This can reduce the battery life.

When you plug in, the charge indicator will appear on the bracelet screen, a battery icon with an animation of filling.

Usually, the problem lies in contaminated contacts or faulty cable. If the bracelet still does not respond, try resetting it to factory settings through the Mi Fit app (Device Profile → Reset).

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Before you first charge a new bracelet, it is recommended to discharge it to 0% and then charge it to 100%, which helps calibrate the battery controller and prolong its life.

How long to charge Mi Band 4 and how to check the charge level

The full charge time of the Xiaomi Mi Band 4 depends on the current battery level and power source.

When you complete the charge, you have a 100 percent permanent battery icon (the animation disappears) and then you can turn off the bracelet, which is impossible to recharge due to the built-in protection.

Check the current level of charge can be in several ways:

• 📱 Through the Mi Fit app: Open the Profile tab → Choose your bracelet → battery-set.
• 🔄 On the bracelet itself: swipe down the screen to open the menu and find the battery icon.
• 🔋 When connecting to charging: the current percentage will be displayed on the screen.

⚠️ Warning: If the bracelet shows 100% charge but discharges quickly (e.g., from 100% to 20% per hour), this is a sign of battery wear.

Typical charging errors and how to avoid them

Even experienced users sometimes make mistakes that shorten the life of the Mi Band 4, and here are the most common ones:

1. Use of non-original cables. Cheap counterparts often have the wrong polarity or poor soldering quality, which leads to overheating of contacts. The original Xiaomi cable has a 10 kOhm resistor between plus and minus contacts, which is protection against short circuit.
2. Charging from powerful adapters (2A Although the bracelet is protected, constant high-current charging accelerates the degradation of the battery. 5V/1A or USB-port.
3. If you turn off the bracelet at 50-70% charge, the battery controller may miscalibrate, causing the device to show the wrong charge level.
4. Charging at extreme temperatures: The optimal temperature for charging is from +10 °C to +35 °C. Charging in the cold (for example, if the bracelet is brought from the street in winter) can damage the battery.

Another common problem is that the bracelet doesn't turn on after charging, and the reasons may be:

• 🔌 The cable is faulty or poorly connected (check the magnetic mounting).
• 🔋 The battery is completely discharged (try to hold on charging for 10-15 minutes, then press the button).
• 🔄 Firmware failure (requires a reset via Mi Fit).

How to extend the battery life of Mi Band 4

The Mi Band 4 battery has a capacity of 135 mAh and is designed for 300-500 charging cycles, but if used correctly, this life can be increased by 1.5-2 times.

• 🔄 Avoid full discharge. Optimal range of 20 to 80 percent. Regular discharge to 0% reduces battery life.
• ⚡ Don't keep charging longer than necessary. Once you reach 100%, turn off the bracelet - even if the controller turns off the current, a long power connection can heat the battery.
• 🌡️ Avoid overheating. Do not leave the bracelet on charge in direct sunlight or near heat sources (for example, on a heating battery).
• 📵 Turn off unnecessary functions. Constant sync with your phone, notifications and sleep monitoring consume charge. Configure them in the Mi Fit app to suit your needs.

It is also useful to calibrate the battery every 2-3 months: completely discharge the bracelet before turning off, then charge to 100% without interruption, which helps the controller to accurately display the charge level.

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The average life of the Mi Band 4 battery, when properly operated, is 2-3 years, and then the capacity is reduced by 30-40%, and the bracelet requires more frequent charging.

If you notice that the bracelet began to discharge in a few hours (instead of the usual 10-14 days), this may indicate:

• 🔋 Battery wear (replacement required).
• 📱 Firmware failure (try to update the software via Mi Fit).
• 🔌 Contact problems (clean them with alcohol).

Frequent questions about charging Mi Band 4

Where to buy the original cable for Mi Band 4 and how much it costs

The original Xiaomi Mi Band 4 cable can be purchased in several locations:

When buying on AliExpress, pay attention to:

• 🛒 The seller's rating must be at least 98%.
• 📦 Number of orders - the more, the more reliable.
• 💬 Photo reviews – check that customers receive original packaging.

Avoid vendors who offer cables under 250 rubles - most likely a fake with low soldering quality.

• 🏷️ Marking MD-Y01 packed.
• 🔍 Mi logo on a magnetic connector.
• 📏 The cable is exactly 20 cm long (for fakes, it is often shorter or longer).

⚠️ Warning: Fake cables can not only charge the bracelet poorly, but also damage its power controller, in which case repairs will cost more than buying the original cable.

Alternative charging methods (if there is no original cable)

If the original cable is lost or broken and it is temporarily impossible to buy a new one, alternative methods may be used, but remember that they do not guarantee safety and can damage the bracelet.

Method 1: Using a cable from Mi Band 3 with modification

The Mi Band 3 and Mi Band 4 cables are visually similar, but they have different layouts.

1. Carefully open the plastic case of the connector (you can use a knife or tweezers).
2. Change the + and - wires (usually red and black).
3. Seal the case with tape and check the polarity with a multimeter before connecting.

Method 2: Charging from a universal magnetic cable

Some universal magnetic cables (such as those for the Huawei Band) may be suitable, but:

• ✅ Check the voltage – it should be. 5V.
• ❌ Do not use cables with a voltage higher 5.5V — It'll knock out the bracelet.

Method 3: Direct connection to power supply (for experienced)

If you have soldering skills, you can connect the bracelet directly to the 5V source via the contacts on the capsule.

+ (red wire) → right contact (if you look at the Mi logo)




- (black wire) → left contact

⚠️ This method is risky, and an error in polarity or voltage will cause permanent damage to the bracelet.

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Any alternative charging options are a temporary solution, so get the original cable as soon as possible to avoid battery problems.