Xiaomi Mi Band 4: How much does the charge actually hold? Tests, comparisons and savings secrets

The Xiaomi Mi Band 4 fitness bracelet remains one of the most popular gadgets for tracking activity even years after its release, its main advantage is the combination of functionality and affordable price. But there is a parameter that worries users the most: how much charge this bracelet holds in real conditions? Official data from Xiaomi promises up to 20 days of operation, but in practice the numbers can be very different.

In this article, we will not only look at the passport characteristics of the Mi Band 4 battery, but also the results of independent tests, factors affecting autonomy, and give specific recommendations on how to extend the life without recharging, you will learn why some users have a bracelet lasts a week, and others almost a month, and what to do about it.

We’ll focus on hidden power settings that Xiaomi doesn’t advertise, but can increase battery life by 30-40%, and compare the Mi Band 4 to the newer models of the series – should you upgrade for a better battery?

Previous Previous post: What Does Xiaomi Promise?

According to the manufacturer’s specifications, Xiaomi Mi Band 4 is equipped with a lithium-polymer battery with a capacity of 135 mAh. In standard use mode (with heart rate monitoring, notifications and screen lighting when raising your hand), the company declares autonomy for up to 20 days.

But these numbers are the result of lab tests under ideal conditions, and the actual time you work depends on:

• 📱 Telephone synchronization frequency (Bluetooth) LE 5.0 consumes energy even in the background)
• ❤️ Intensities of pulse measurement (continuous monitoring vs. manual measurements)
• 🔦 Brightness and activity time AMOLED-screen (0.95 inch, resolution 120×240)
• 🚶 Type of activity (stepmeter and GPS-Tracking through a smartphone discharges the battery faster)

It is important to understand that the Mi Band 4 does not have a built-in GPS-Module – it uses smartphone data to track jogs, which indirectly affects the charge consumption of both devices, and the firmware version also affects the autonomy: early revisions had power-efficient bugs fixed in the 2020-2021 updates.

Real-life tests of autonomy: data from users and experts

Independent tests show that in the average use mode (notifications, automatic pulse monitoring every 30 minutes, screen lighting when raising your hand), the Mi Band 4 holds a charge from 10 to 15 days.

• 🏃‍♂️ With active use (daily training with pulse metering, frequent notifications) – 7-10 days
• 😴 Minimum power consumption (unplugged notifications, manual pulse measurement) – up to 25 days
• 📉 After 1-1.5 years of operation, the battery capacity decreases by 15-20%, which reduces autonomy by 2-3 days.

TechMoan’s interesting results in 2020 were that, with round-the-clock monitoring of sleep, footsteps and heart rate (every 10 minutes), the bracelet worked 12 days and 4 hours, while GSMArena’s test showed 18 days with automatic pulse measurements turned off and rare notifications.

Note: In Always On Display mode, autonomy drops almost 3 times! This feature is only available when manually enabled via the bracelet menu (Settings → Display → Always On).

💡

If you are critically interested in maximum autonomy, turn off automatic pulse measurement at night. For this, in the Mi Fit application, go to Profile → Mi Band 4 → Heart Rate Monitoring → Schedule and set the interval from 23:00 to 7:00 as “off.” This will extend the work for 2-3 days.

What's the worst thing about a battery?-5 "power thieves"

Even if you rarely look at the screen, some features of the Mi Band 4 can unnoticeably drain the battery.

1. Continuous pulse monitoring - eats up to 40% of the charge in 7 days, turned on by default every 30 minutes, but you can reduce the frequency or turn off at night.
2. Frequent notifications – each vibrational alert (even from messengers) consumes ~1% of the charge. At 50 notifications per day, it is minus 2-3 days of autonomy.
3. Illumination of the screen when raising the hand – the motion sensor works constantly, which adds ~15% to the flow rate for the week.
4. Synchronization with Mi Fit – each automatic data update (every 30-60 minutes) wastes energy on a Bluetooth connection.
5. The vibration of the alarm clock is one alarm clock with vibration "eats" ~0.5% of the charge. At 5 alarm clocks per day, it is minus 1 day of autonomy.

Lifehack: If you don’t use incoming call alerts, turn them off in Mi Fit → Notifications → Calls. This will save up to 10% of your charge per week, as the bracelet won’t constantly “listen” to Bluetooth headphones or phone.

⚠️ Note: after updating the firmware Mi Band 4 to version 1.0.9.54 (2021), some users encountered a power-efficient bug. If after the update the bracelet began to run out in 3-4 days, try resetting it to factory settings (Settings) → Reset) or roll back firmware through Mi Fit.

How to extend the battery life: 7 proven ways

If your Mi Band 4 is less than a week old, don't be quick to blame the battery. 80 percent of the time, it's set up. Here's what really works:

Turn off automatic pulse monitoring at night|Reduce the brightness of the screen to 2-3 divisions|Turn off the light when raising your hand|Turn off notifications from unnecessary applications|Synchronize data manually (1-2 times a day)|Use dark dials (AMOLED more economical shows black)|Turn off the vibration for alarms if you don’t need it-->

1.Pulse monitoring setup

By default, the bracelet measures the pulse every 30 minutes. Change the interval by 1 hour or turn off night monitoring:

Mi Fit → Profile → Mi Band 4 → Heart Rate Monitoring → Interval

This will extend the autonomy for 3-5 days.

2. Screen optimization

AMOLED-The Mi Band 4 display consumes less power when displaying dark colors. Set a black-backed dial (like Simple Black or Digital Dark) and reduce the backlight time to 5 seconds:

Bracelet settings → Display → Brightness (2–3 divisions) → Backlight time (5 seconds)

3. Notification management

Turn off alerts from unnecessary apps (social networks, games, emails) and leave only calls and SMS:

Mi Fit → Notifications → Select applications

Each extra notification reduces autonomy by 1-2 hours.

⚠️ Note: if you use Mi Band 4 to pay via Mi Pay, disabling Bluetooth sync will make it impossible to make a payment).

Comparison with other models: should I upgrade?

If you don't like the autonomy of the Mi Band 4, should you upgrade to newer models?

Paradoxically, despite the increased battery capacity in the Mi Band 7 (180 mAh vs. 135 mAh in version 4), the actual autonomy has increased slightly, due to a more energy-intensive processor and a bright screen, so the Mi Band 4 remains one of the leaders in terms of time among the entire lineup.

If you are interested in autonomy, it makes sense to consider alternatives:

• 🔋 Amazfit Bip U Pro – up to 9 days with active use, but with a GPS
• ⚡ Huawei Band 6 – 14 days, but with a more accurate pulse sensor
• 💰 Xiaomi Mi Band 4 NFC — same autonomy, but with support for contactless payments

💡

The Mi Band 4 remains the best choice for price, functionality and autonomy. New models offer better screens and sensors, but a slight increase in operating time does not justify an upgrade if you are satisfied with the current autonomy.

How to charge correctly: myths and reality

Many users misuse the Mi Band 4 battery, which causes it to wear out quickly.

Myth 1: “You have to completely discharge the bracelet before charging.”

This is true for older nickel-metal hydride batteries, but not for lithium-polymer batteries (as in the Mi Band 4); the optimal mode is to charge at 20-30% and turn off at 80-90%; full cycles (0-100%) reduce battery life.

Myth 2: “Taking a charge all night will damage the battery.”

The Mi Band 4 has a controller that shuts down power after reaching 100%, but if left on charge for a few days, it can overheat, and the optimal is to charge 1.5-2 hours to full levels.

Proper charging:

• ⚡ Use only the original cable (non-original cables can damage the power controller)
• 🔌 Charge from the network adapter, not from USB-PC port (power may not be enough)
• 🌡️ Avoid charging at temperatures below 0°C or higher than 40°C
• 📵 Do not use the bracelet while charging (this may cause firmware failure)

The average time to fully charge the Mi Band 4 is 1.5-2 hours, and if it takes more than 3 hours, it is a sign of battery wear or cable problems.

FAQ: Answers to Frequent Questions