The Xiaomi Mi Band 4 fitness bracelet remains one of the most popular wearables even years after its release, with its top selling points being affordable, wide-ranging functionality and, of course, the manufacturer's stated autonomy of up to 20 days. But in practice, users often find that the charge is much less. Why is this happening? And how do you get maximum time from a single charge?
In this article, we will analyze the real-life battery tests of the Mi Band 4, analyze what is eating the battery, and give you specific optimization recommendations, learn how to properly charge the bracelet, what settings affect energy consumption, and what to do if the device starts to run too fast, and compare the Mi Band 4 with newer models in terms of running time.
Official data vs reality: how much does the Mi Band 4 charge hold?
The manufacturer claims that the Xiaomi Mi Band 4 can last up to 20 days on a single charge, but this figure is more of a marketing ploy than a real indicator. In the laboratory (minimal activity, disabled notifications, rare synchronizations), the bracelet can indeed pull close to this value, but in everyday use, the situation is different.
According to independent tests and user reviews, the average battery life of the Mi Band 4 is:
- 🔋 7–10 days - with active use (notifications, sleep monitoring, pulsemeter) 24/7, frequent synchronization)
- 🔋 12-15 days - with moderate use (notifications only from calls, pulse meter on request, synchronization 1-2 times a day)
- 🔋 18-20 days - in "economical" mode (disabled notifications, manual start of measurements, rare synchronization)
It is important to understand that even two identical bracelets can have 20 to 30 percent different autonomy due to the individual characteristics of the battery, the firmware version and operating conditions, for example, at temperatures below +10°C, the battery capacity is temporarily reduced by 15 to 20 percent, which leads to faster discharge.
What affects battery consumption: top-5 "charge-eater
If your Mi Band 4 is running out too quickly, check these settings and features first, which are the most common causes of reduced autonomy:
- Continuous heart rate monitoring, a pulsemeter running in the background 24/7 can eat up to 30% of the charge per day, especially if you have a measurement interval more than once every 10 minutes.
- Each vibrational alert (call, SMS, messenger) consumes 1-2% of the charge. With an active notification stream (50+ per day), this can reduce autonomy by 2-3 days.
- If the Mi Fit application settings enable automatic data exchange (for example, every 30 minutes), the bracelet will often “wake up” to transmit information, which increases energy consumption by 15-20%.
- Brightness of the display above 70% and long backlight time (more than 5 seconds) can reduce autonomy by 10-15%, especially at night, when the bracelet often "wakes up" from random movements.
- In the early versions of the software for Mi Band 4 were bugs that led to increased battery consumption (for example, incorrect operation of sensors). Updating to the latest firmware can add 1-2 days of autonomy.
Another hidden charge eater is Bluetooth malfunctioning. If the bracelet is constantly losing touch with the phone and trying to reconnect, it can increase power consumption by 25-30%. To check this, open Settings → Bluetooth on the phone and see if the Mi Band 4 is displayed as an unconnected device.
How to check the firmware version of Mi Band 4?
How to Charge Mi Band 4: Myths and Reality
Many users believe that the way you charge it depends on how long the battery lasts, so let's figure out what's true and what's a common misconception.
✅ What's really important:
- 🔌 Use the original cable. Cheap analogues can not only charge slower, but also damage the contacts of the bracelet.
- 🔋 Do not discharge to 0%. It is optimal to start charging at 10-20% - this prolongs the battery life.
- ⚡ Charge at room temperature (15–25)°Charging in cold or heat accelerates battery degradation.
❌ Common myths:
- ❌ "You need to completely discharge the bracelet once a month" - this is relevant for nickel batteries, and in the Mi Band 4 there is a lithium-polymer battery, which is only harmed by a deep discharge.
- ❌ "Charging overnight spoils battery – the bracelet has a controller that turns off power after 100%, so overcharging is impossible.
- ❌ "You need to disconnect the bracelet from charging immediately after 100%" - modern devices automatically stop charging, so you should not worry about it.
Please note the charging indication:
- 🟢 Green light - bracelet charged.
- 🔴 Red light – charging error (check contacts or cable).
- No indication - it is possible that the bracelet is completely discharged (wait 5-10 minutes, if the indicator does not appear, try another cable).
💡
If the bracelet is not charging, try to clean the contacts on the bracelet and charger with a cotton swab dipped in alcohol, often the problem lies in oxidation or contamination.
Autonomy Test: Real numbers under different scenarios
To understand how much the Xiaomi Mi Band 4 actually holds, we tested it in three modes of use, all on a bracelet with the latest firmware (1.0.9.58) and synchronization with the Redmi Note 10 Pro phone.
| Mode of use | Settings | Time of autonomy | Daily expenditure |
|---|---|---|---|
| Intense | Pulsemeter 24/7 (every 5 minutes) Notifications from all applications Lighting 10 seconds, brightness 100% Synchronization every hour | 5 days 12 hours | ~18% |
| Balanced | Pulsemeter every time 30 Mins Notifications from calls only/SMS Illumination 5 sec, brightness 70% Synchronization 2 day-to-day | 11 days 8 hours | ~8% |
| Economical | Pulsemeter manual Notifications disabled Lighting 3 seconds, brightness 50% Synchronization 1 time per day | 18 days 3 hours | ~5% |
Interesting fact: in economical mode, the bracelet consumes energy almost as much as in standby mode (without active use), which suggests that the main expense is not for background processes, but for user interaction (lighting, vibration, synchronization).
If your Mi Band 4 discharges faster than the test, it may indicate:
- 🔋 Battery degradation (if the bracelet is more than 2-3 years old)
- 📱 Bluetooth problems on your phone (constant reconnection)
- 🐛 Firmware failure (will help reset or flashing)
How to Extend Autonomy: Step-by-step Optimization
If you’re not happy with how much charge your Mi Band 4 holds, follow this checklist.Even small changes can add 2-5 days of battery life.
Turn off continuous pulse monitoring |Reduce screen brightness to 50-70% |Reduce backlight time to 3-5 seconds |Deactivate notifications from unnecessary applications |Install sync 1-2 times a day |Update firmware to the latest version |Check Bluetooth connection for stability
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Let's take a closer look at each item:
- Turn off continuous heart rate monitoring Go to Device Profile → Heart Rate Monitoring and select Manual or Every 30 Minutes mode. This will save up to 25% of your charge per day.
- Set up notifications to Profile → Leave only the most important notifications (calls, SMS, 1-2 messengers). Each extra alert is 1-2% charge.
- Reduce brightness and backlight time In Profile → Setting the screen brightness by 50-70% and backlight time by 3-5 seconds. This will add 10-15% autonomy.
- Limit synchronization to Profile → Autosynchronization choose the interval of 12 or 24 hours. Frequent synchronization "wakes" the bracelet and wastes charge.
- Check Bluetooth connection If the phone is constantly losing touch with the bracelet (for example, due to long distance or interference), Mi Band 4 will waste energy on reconnections. Make sure that the distance between the devices does not exceed 10 meters, and the phone does not have active VPN or energy saving mode that blocks the background work of Mi Fit.
💡
The most effective way to extend autonomy is to turn off continuous heart rate monitoring, which gives you an increase of up to 3-4 days of operation without recharging.
If even after optimizing the bracelet discharges too quickly, try resetting it to factory settings:
1. In the Mi Fit app, go to the Device Profile → Untie the device.
2. on the bracelet, reset: press the touch button for 10 seconds until vibration appears.
3. Reconnect the bracelet and set it up from scratch.
⚠️ Warning: After resetting, all data on the bracelet (steps, sleep, exercise) will be deleted. If it is not synchronized with the application, it will be impossible to restore it.
Comparison with other models: who holds the charge longer?
If you’re considering buying a new bracelet and are wondering if you should stay on the Mi Band 4, let’s compare its autonomy to more modern models from Xiaomi:
| Model | Battery capacity (mAh) | Declared autonomy | Real autonomy (with moderate use) | The increase compared to the Mi Band 4 |
|---|---|---|---|---|
| Mi Band 4 | 135 | 20 days | 10-12 days | — |
| Mi Band 5 | 125 | 14 days | 8-10 days | ↓ for 2-3 days |
| Mi Band 6 | 125 | 14 days | 7-9 days | ↓ for 3-4 days |
| Mi Band 7 | 180 | 15 days | 10-12 days | ≈ at Mi Band 4 level |
| Mi Smart Band 8 | 190 | 16 days | 12-14 days | ↑ for 2-3 days |
As you can see from the table, Mi Band 4 The secret to the autonomy is not inferior to newer models, and in some cases even surpasses them, the secret lies in the optimization of firmware and the lack of energy-intensive functions (for example, the Mi Band). 6/7 more vividly AMOLED-screen and advanced sensors, which increases battery consumption).
If you’re critical to autonomy, switching to the Mi Band 8 will only give you 2-3 days of gain, whereas the price difference can be significant, in which case it makes sense to stay on the Mi Band 4 and just optimize its settings.
⚠️ Attention: In Mi Band models 5/6/7 magnetic charging is used, which is more convenient, but the charging process itself takes on a 30–40 Minutes longer than the Mi Band 4 (1.5–2 hourly 1 hour).
Frequent battery problems and their solutions
If your Xiaomi Mi Band 4 is running too fast or is not behaving as it should, check out these typical problems:
🔋 The bracelet discharges in 1-2 days
Possible causes and solutions:
- 📱 Phone sync failure – remove the bracelet from the list of Bluetooth devices on the phone, then reconnect it via Mi Fit.
- 🔄 Cycle process – reset the bracelet (press the button for 10 seconds) and set it up again.
- 🔋 Battery degradation – if the bracelet is more than 2-3 years old, it may be time to replace the battery (in the service center it is worth it). ~1000-1500 rubles).
🔌 Bracelet not charging
What to do:
- Check the cable and power supply (try charging from another) USB-port).
- Clean the contacts on the bracelet and charger with a cotton swab dipped in alcohol.
- Wait 10-15 minutes – if the bracelet is completely discharged, the charging indication may not appear immediately.
- If nothing works, try charging a power bank bracelet or other bracelet. USB-devices (sometimes the problem is unstable voltage from the socket).
📉 Charge "sinks" (for example, from 50% immediately to 10%)
This is a typical sign of a battery calibration that's not right.
- Discharge the bracelet until it is completely switched off.
- Charge it to 100% without interruptions (do not disconnect from charging until the green indicator lights up).
- Repeat the discharge / charge cycle 2-3 times.
If the problem remains, reset the bracelet to factory settings.
💡
If the bracelet began to discharge quickly after updating the firmware, try to roll back to the previous version. To do this, in the Mi Fit application, go to Profile → Software Update and select the rollback option (if available).