Xiaomi Mi Band 4 is one of the most popular fitness bracelets on the market, combining affordable price, functionality and long life on a single charge. However, even such a simple device requires proper handling, especially when it comes to charging. Failure to follow basic recommendations can lead to rapid battery wear, malfunctions or even breakdown of the gadget.
In this article, we will explore all the nuances of charging the Mi Band 4, from choosing a charger to optimal connection time, learn how to avoid typical errors, prolong battery life and what to do if the bracelet is not charged, and answer frequent questions from users who face problems in operation.
Even if you think it's easy to charge the bracelet, some things (such as ambient temperature or using unoriginal cables) can play a key role. So let's get this straight.
Technical characteristics of the Xiaomi Mi Band 4 battery
Before we talk about charging properly, it’s worth understanding what battery we’re dealing with. The Mi Band 4 is equipped with a 135mAh lithium polymer battery. This is not the biggest number, but thanks to optimized power consumption, the bracelet can last up to 20 days in standard mode (with notifications, sleep monitoring and steps).
Key Battery Parameters:
- 🔋 Type: Li-Po (lithium-polymer)
- 📏 Capacity: 135 mAh (nominal)
- ⚡ Voltage: 3.85 V
- 🔄 Charging cycles: up to 500 full cycles (when operated correctly)
It is important to understand that the actual battery life depends not only on the number of cycles, but also on the charging conditions. For example, maintaining a charge at 100% or a discharge to 0% reduces the battery life.
It is also worth noting that the Mi Band 4 does not support fast charging – a full cycle takes about 1.5-2 hours when using the original cable, due to the current restriction that is embedded in the device’s power controller.
What Charger to Use for Mi Band 4
One of the most common questions users ask is whether you can charge the bracelet with a non-original cable or an adapter, and the answer depends on several factors, but in general, the manufacturer recommends using only a component cable.
- ⚡ Voltage compatibility: the original cable provides stable 5V/0.5And what's safe for the power controller of the bracelet, cheap analogs can give off power surges.
- 🔌 Contact density: Non-original cables often use thinner spring contacts that loosen over time and are poorly fixed.
- 🛡️ Protection against overheating: branded cable has built-in protection against short circuit and overheating, which is not in most cheap analogues.
If the original cable is lost or broken, it is best to purchase a certified replacement from Xiaomi or proven brands (like Baseus or UGREEN). avoid nameless cables from AliExpress or markets - they often cause breakdowns.
Also, note the charging connector. The Mi Band 4 has a two-pin magnetic connector (like the earlier Mi Band 2/3 models). If you use a charging device from the Mi Band 5/6, it won't physically fit, the contacts are different.
⚠️ Warning: Never try to charge the bracelet through USB-port of the computer, if the cable is not designed for this. USB-port using homemade adapters - this can disable the power controller.
Step-by-step: how to charge the Xiaomi Mi Band 4
Now, let's get to the practice. Charging the bracelet consists of a few simple steps, but even here there are nuances that will help to avoid problems.
- Prepare the bracelet: remove the capsule from the strap, carefully pulling it towards the screen. Don't put too much effort into it - the locks are quite fragile.
- Cable connection: combine the contacts on the back of the bracelet with the contacts on the charger. Magnets will help to lock the position, but make sure the connection is tight.
- Power supply connection: use an output adapter 5V/1A or 5V/0.5A. Can be charged from USB-computer port, but charging time will increase.
- Control: The charge indicator (battery animation) will appear on the bracelet screen. If the indicator is not on, check the density of contacts or try another cable.
☑️ Checklist before charging Mi Band 4
While charging, the bracelet may get a little warmer — that's normal. However, if the case gets hot (over 40°C), immediately disconnect it from the power supply, which may indicate a malfunction of the battery or cable.
It is also not recommended to charge the bracelet in high humidity conditions (for example, in the bathroom after shower) or when direct sunlight is injected. The optimal temperature for charging is 10-35 ° C.
How long to charge Mi Band 4 and how to know if charging is complete
The full charging time of Xiaomi Mi Band 4 depends on several factors:
- 🔌 Power supply: from the adapter (5V/1And) — 1.5–2 hourly USB-PC port - before 3 hours.
- 🔋 Current charge level: If the battery is discharged to 0%, the time will increase by 20-30%.
- 🌡️ Ambient temperature: at low temperatures (below 10)°C) the process is slowing down.
The completion of the charging signal:
- 📱 100% on the bracelet screen (it says "Full" or a full battery appears).
- 🔌 The indicator on the charger (some cables LED goes out or changes color).
- 📲 Notification in annex Mi Fit/Zepp (If the bracelet is synchronized with the smartphone).
The critical point: do not leave the bracelet on charging more than 4-5 hours after reaching 100%. Lithium polymer batteries do not like long stays in a state of full charge - this reduces their life.
| Charge level when connected | Charging time (from the adapter 5V/1A) | Charging time (from USB PC) |
|---|---|---|
| 0–10% | 1 hour 50 min - 2 hours 10 min | 2 hours 30 minutes 3 hours |
| 20–30% | 1 hour 20 minutes - 1 hour 40 minutes | 2 hours - 2 hours 20 minutes |
| 50–60% | 40-50 minutes | 1 hour - 1 hour 10 minutes |
| 80–90% | 20-30 minutes | 30-40 minutes |
If the bracelet does not charge longer than the specified time, check:
- 🔌 Cable and adapter (try charging another device).
- 🧹 Cleanliness of contacts (wipe with an alcohol napkin).
- 🔄 Reset the bracelet (press the touch button for 10 seconds).
Typical charging errors and how to avoid them
Even experienced users sometimes make mistakes that shorten battery life or render the bracelet inoperable, and here are the most common ones:
- 🔥 Use of damaged cable: bare wires or cracks in the insulation can cause a short circuit. Always inspect the cable before connecting.
- ❄️ Charging at extreme temperatures: below 0°C or higher than 45°C. This may cause irreversible damage to the battery.
- 🔋 Continuous 100% charge: If the bracelet is always connected to charge (e.g. at night), the battery degrades faster.
- 💦 Moisture on contacts: even if the bracelet has protection IP68, wet-loading is dangerous.
Another common problem is that the bracelet doesn't turn on after it's completely discharged.
- Connect it to charging for 15-20 minutes (sometimes it takes time for the controller to wake up).
- Use a different cable and adapter.
- Press and hold the touch button for 10-15 seconds to force reboot.
⚠️ Warning: If the bracelet does not respond to charging for more than a day, do not try to disassemble it yourself. Contact the service center - there may be a failure of the power controller or a deep discharge of the battery.
💡
If the bracelet is quickly discharged, try to reset it to factory settings through the Mi Fit application. Sometimes failures in firmware lead to increased power consumption.
How to extend the battery life of Mi Band 4
Lithium polymer batteries lose capacity over time, but proper operation can slow this process.
- 🔄 Avoid full discharge cycles: try to recharge the bracelet at 20-30% charge, rather than waiting for it to sit down completely.
- 🌡️ Store the bracelet at room temperature: if you do not use it for a long time, remove it from charging at 40-60% charge and put it in a dry place.
- ☀️ Don’t leave it in the sun: Direct rays heat the battery, which accelerates its degradation.
- 🔌 Use high-quality adapters: cheap charging with unstable voltage spoils the power controller.
You should also turn off unnecessary functions if you notice that the bracelet began to discharge faster:
- 📱 Constant sync with your phone (reduce the update frequency in Mi Fit).
- 🔦 Illumination of the screen when raising your hand (replace with button control).
- 💤 Real-time sleep monitoring (unplug if needed).
The average battery life of the Mi Band 4 when properly operated is 2-3 years, after which the capacity decreases markedly and the bracelet requires more frequent charging. If the battery starts to run down in 1-2 days (during normal use), this is an occasion to consider replacing the battery or buying a new device.
What to do if the bracelet is discharged in a few hours?
Frequent problems and their solutions
Even with proper charging, Mi Band 4 users sometimes experience problems, and let’s look at the most common ones and how to fix them.
| Problem. | Possible cause | Decision |
|---|---|---|
| Bracelet not charging | Cable damaged, contacts contaminated, software failure | Try another cable, wipe the contacts with alcohol, reload the bracelet |
| Charging takes too long. | Used weak power supply (USB PC), faulty battery | Connect to the 5V/1A adapter, check the status of the battery |
| The bracelet overheats when charging | Unoriginal cable, damaged battery | Turn off the power, let it cool, use the original cable |
| After charging, the bracelet does not turn on. | Deep discharge, power controller failure | Hold on charging for 20-30 minutes, try rebooting |
| The charge level “jumps” (for example, from 50% to 20%) | Failure of battery calibration, battery wear | Completely discharge and charge the bracelet 2-3 times in a row |
If neither of these methods worked, you may need to replace the battery or power controller. In official Xiaomi service centers, this service costs 800-1,500 rubles (depending on the region). Self-repair is not recommended - there is a high risk of damage to the board or display.
Also worth mentioning is the bracelet firmware, which sometimes causes charging or autonomy issues after a software update via Mi Fit, in which case you can roll back to the previous firmware version with special utilities (such as Mi Band 4 Tools), but this requires certain skills.
💡
If the bracelet stopped charging after falling or getting moisture, do not try to turn it on - this can lead to a short circuit.