The Xiaomi Redmi Note 8 Pro, with its capacious 4500mAh battery, has long been a cult device, but even the most reliable batteries degrade over time. If your smartphone starts to run out in half a day, overheat when charging or suddenly turn off by 30-40%, it’s time to check the battery health. In this article, 7 working diagnostic methods, from hidden engineering menus to professional applications, as well as unique codes for the Redmi Note 8 Pro (begonia model), which do not work on other Xiaomi smartphones.
We're going to look at not only software, but physical signs of wear that are often ignored. For example, did you know that the bloating of the battery on the Redmi Note 8 Pro is not only a convex body, but also a characteristic creak when you press the screen? Or that a battery health unknown error on the engineering menu can mean both a controller malfunction and a banal contamination of contacts? At the end of the article, an FAQ with answers to thorny questions, including "can we restore capacity" and "is it worth changing the battery itself."
1.Secret Code Verification (Redmi Note 8 Pro only)
The fastest way to get data about the battery is to use service USSD-Importantly, the codes may differ for other Xiaomi smartphones, even from the same Note line.
Open the phone application and enter:
- 🔢 ##4636## is the main engineering menu. Go to the Battery information tab. This displays the current charge level, temperature, voltage and charging technology (e.g. Quick Charge 3.0).
- 📊 ##6484## is a battery test, which shows the actual capacity in mAh (compare with the passport 4500 mAh) and the number of charging cycles.
- ⚡ ##36446337## - menu MIUI Battery: You can see the health status (Good to Replace Soon) and the time you're fully charged at your last cycle.
⚠️ Note: If a message is sent to Connection Problem or Unusable after entering the code MMI code, so your firmware has blocked the engineering menu, so the solution is to patch it through Magisk or use alternative methods in the following sections.
2.Diagnostics through applications (AccuBattery, CPU-Z, AIDA64)
Service codes provide basic information, but for deep analysis, it's better to use specialized tools that track capacity degradation, discharge rates, and even temperature anomalies.
Top.-3 apps for Redmi Note 8 Pro:
- 📱 AccuBattery – shows real capacity (for example, 3800 mAh instead of 4500), wear and health scores, features: takes charge cycles into account and offers optimal thresholds (20–80%) for extending battery life.
- 🔍 AIDA64 — Battery displays Li-Poly, voltage, temperature, and status (e.g. Charging: AC). Plus: It works without root rights.
- 📊 CPU-Z — Battery tab shows charge level, state (Health) and current consumption in mA. Minus: does not save history.
💡 Tip: For accurate data, before the test, fully discharge the smartphone before turning off, then charge to 100% without using.
☑️ Preparation for battery test
3. Visual signs of battery wear
Battery problems aren't always visible in software. Physical symptoms often appear before the capacity drop.
| Sign. | What does it mean? | Risk level |
|---|---|---|
| The body is swollen (the gap between the screen and the frame is visible) | Critical battery bloating, risk of damage to the screen and motherboard. | ❌ Immediate replacement! |
| The phone is spontaneously turned off by 20-40% | Failure of the charge controller or severe degradation of the capacity. | ⚠️ Requires diagnosis |
| Overheating during charging (>45°C) | Failure of the battery or charger, there is a risk of fire. | ❌ Dangerous! |
| Screaming or crunch when pressed on screen | Initial swelling. The battery is pressing on the display. | ⚠️ Should be replaced |
⚠️ Warning: If you notice bloating, do not try to push the battery back or pierce it! Lithium polymer batteries can ignite if damaged. The only solution is to turn off the phone and take it to the service.
What if the battery is swelling and there is no service nearby?
4. Load test: how to check real working hours
Programs show capacity, but how do you know how much your Redmi Note 8 Pro will actually run on a single charge?
- Charge your phone to 100% and disconnect from the network.
- Turn on the plane mode, but leave it active: 📱 Screen (brightness 50%) 🎵 Music playback (through speakers) 📡 Wi-Fi (connect to the network, but do not use the Internet)
Redmi Note 8 Pro
8:10 hours
🔋 If the phone is discharged in 3-4 hours even in standby mode (without active use), this means that the battery wear has exceeded 60% - it's time to think about replacing it.
💡
For a more accurate test, use the PCMark Battery Test app, which simulates real-world use cases (web surfing, video, games) and gives you a score of autonomy.
5. Battery calibration: when and how to make it
Sometimes the problem is not wear, but a charge controller failure, which causes the phone to show the wrong percentage, such as a charge jumps from 50% to 20% or a smartphone turns off by 30%, in which case calibration will help.
Instructions for Redmi Note 8 Pro:
- Discharge the phone before automatically shutting down.
- Connect the original charger and wait for the charging indicator to appear (usually in 5-10 minutes).
- Turn on your phone and reset your battery settings: Settings → Battery and Performance → Battery settings → Reset battery statistics
- Charge to 100% without interruption (don’t turn off the cable!).
- Turn off the charger and use the phone until it is completely discharged. Repeat the cycle 2-3 times.
⚠️ Important: Do not leave your phone on charge from the power bank for the whole night - after 100% turn off to avoid overcharging.