How to check the battery status of Xiaomi Redmi Note 7: from engineering menu to hidden codes

Xiaomi Redmi Note 7 is one of the most popular smartphones of 2019, but its battery capacity of 4000 mAh after 3-4 years of operation begins to lose capacity. If your phone runs out in a few hours, turns off at 20-30% charge or overheats during charging, it’s time to diagnose the battery. In this article, you will find 5 proven ways to assess its condition without disassembling the device.

We’ll break down the official and hidden methods, from built-in MIUI tools to engineering codes and third-party applications. Importantly, test results may vary depending on the firmware version (MIUI 10/11/12/13/14) and the degree of battery wear. All instructions are relevant for the Redmi Note 7 (codenamed lavender) and Redmi Note 7 Pro (violet).

1. Check through the standard MIUI menu: quick inspection

The easiest way is to use the built-in MIUI tools, which won't show the exact percentage of wear and tear, but will help identify obvious battery problems.

Open Settings → Battery and Performance → Battery status. Here you will see three key parameters:

  • 🔋 Charge level – current percentage in real time.
  • ⚡ Temperature - normal range: 25-40°C when charging and 15-35°C to simple. If the values are higher, the battery overheats.
  • ⏳ Operating time - approximate autonomy time at current charge level (calculated based on recent discharge cycles).

Look at the consumption schedule over the past 24 hours. Dramatic discharge surges (e.g., a drop from 80% to 50% in 10 minutes) indicate a power controller malfunction or a heavy wear of cells. If the schedule is missing, upgrade the firmware to MIUI 12 or later.

⚠️ Note: In some versions MIUI The battery state section may not be there. It's not a mistake -- the manufacturer hides it on devices older than 3 years.

2. Engineering menu: hidden data about the battery

The engineering menu (#4636##) contains detailed battery information that the standard settings don’t show.This method works on all versions of the Redmi Note 7, but it takes care not to change the other options on the menu!

Instructions:

  1. Open the Phone app.
  2. Enter the combination: ##4636## (no call required).
  3. Select Battery Information (Battery Information).

In the window that opens, pay attention to the following parameters:

ParameterNormal value.What does deviation mean?
LevelCorresponds to the current % chargeIf it is very different from what is displayed in the status bar – calibration failure
Voltage3.7-4.2 V (at 100% charge)Below 3.5 V - deep discharge, above 4.3 V - recharge
Temperature250–400 (25–40°C)Above 450 - overheating, below 150 - cold battery
HealthGoodUnknown or Dead - Critical Wear

If you don't have a Health option, your version of MIUI doesn't support displaying it, in which case you can switch to the ADB method (Section 4).

📊 How often do you check the battery status of your smartphone?
Once a month
Only when the problems start.
Never checked.
I don't know how to do that.

3. Diagnostic applications: AccuBattery and AIDA64

The app side provides more detailed information than the standard tools, and we recommend two proven options:

AccuBattery (free version with limitations):

  • 📊 Shows the real battery capacity in mAh (compared to the passport capacity of 4000 mAh).
  • 🔄 Tracks charging cycles (norm - up to 500 cycles for lithium-polymer batteries).
  • ⚡ Analyzes charging/discharge rate (normal for Redmi Note 7: 10–18 W).

AIDA64 (paid version):

  • 🔍 Shows battery technology (for Redmi Note 7 - Li-Polymer).
  • 📅 Displays the date of first use (helps estimate the age of the battery).
  • 🌡️ Monitors the temperature in real time with graphs.

How to use AccuBattery:

Install the app from Google Play| Run and allow all access requests | Charge your phone to 100% (without turning off charging) | Wait for the automatic capacity test (takes 1-2 charging cycles) | Check the Health section for wear-->

Important: for accurate results, use the application for at least 3-5 days. A one-time check can give false data due to temporary voltage surges.

⚠️ Attention: Some applications (e.g, CPU-Z) This shows the incorrect battery capacity for Xiaomi devices, due to the limitations of access to system data in the MIUI. Trust only AccuBattery or AIDA64.

4. ADB-Teams: Data for Advanced Users

If the engineering menu doesn't show you Health, and you don't trust the apps, use ADB, which requires you to connect your phone to your computer, but it gives you the most accurate data.

Instructions:

  1. Download and install Google’s Platform Tools.
  2. Enable USB Debugging in the Developer Settings → About Phone → MIUI Version – Press 7 times, then go back to Additional Settings → For Developers.
  3. Connect your phone to your PC and open the command line in the adb.exe folder.
  4. Enter the command: adb shell dumpsy battery

In conclusion, find the following lines:

health: 2


present: true




status: 2




technology: Li-polymer




voltage: 4123

Transcript:

  • health: 2 - battery condition (2 = good, 3 = overheating, 4 = dead, 7 = cold).
  • Voltage is the current voltage in millivolts (4123 mV = 4.123 V).
  • Technology: A type of battery (should be a Li-polymer).

If the health is 4 or 7, the battery needs to be replaced. 3 is temporary overheating (check the charger and cable).

adb shell cat /sys/class/power_supply/battery/uevent

It will display similar data in a different format.-->

5. Visual Diagnostics: When to Open Your Phone

If the software methods show critical wear and tear, but you doubt the results, inspect the battery visually, which is an extreme method, as it requires disassembling the device and resetting the warranty (if it is still valid).

Signs of a faulty battery:

  • 🔥 Bloating – the phone body is deformed, the screen “steps away” from the frame.
  • 💧 Electrolyte dashing - white or green plaque on the board near the battery.
  • 🔌 Contact oxidation – green or black coating on the metal contacts of the battery.
  • 🧲 Label detachment – if the battery sticker is swollen or unstuck.

How to open the Redmi Note 7:

  1. Turn off the phone and remove it. SIM-map.
  2. Heat the back cover with a hair dryer (60–80°C) to soften the glue.
  3. Tap the lid with a plastic spatula, starting at the corner near the USB-C connector.
  4. Disconnect the battery plume (it is under the metal plate).

⚠️ Attention: A bloated battery cannot be punctured or compressed - this can cause fire! If you notice a deformation, immediately take the phone to the service center. Xiaomi offers a discount on battery replacement for visual signs of bloating (the action is valid in official service centers).

What if the battery is swelling and there is no service center nearby?
1. Turn off the phone and don't turn it on. 2. Place the device in a non-combustible container (such as a metal can of sand). 3. Don't store near heat sources or other electronics. 4. Contact Xiaomi via an official chat for instructions on safe disposal.

6.Discharge test: how to check the real capacity

If all previous methods have not given a clear answer, run a controlled discharge test, which will show how much your battery really "holds" compared to the passport 4000 mAh.

Instructions:

  1. Charge your phone to 100% and turn off charging.
  2. Turn on Airplane Mode and turn off Wi-Fi/Bluetooth.
  3. Set the screen brightness to 50%.
  4. Run a video in the loop (e.g., a black screen with white text on YouTube).
  5. Keep the time to full discharge (0%).

Compare the result with the reference values:

Battery statusOpening time (screen)Real capacity.
New (0-10% wear)8:10 hours3800-4,000 mAh
Average wear (30–50%)5-7 hours2500-3,000 mAh
Strong wear (70%+)2-4 hours1000–2,000 mAh

If the battery is less than 4 hours old, the battery is critically worn out. Please note that the test must be conducted at room temperature (20-25°C). Cold or heat will distort the results.

💡

A discharge test is the most reliable way to assess the actual capacity, but it takes a long time. For a quick diagnosis, combine it with an AccuBattery test or an engineering menu.

FAQ: Frequent questions about the Redmi Note battery 7

Can the battery be restored after heavy wear?
No, you can't restore the original capacity of the lithium polymer battery, the only way out is to replace it, but you can slow down further wear: 🔌 Avoid charging until 100% (optimally — 80–90%). 🌡️ Do not use your phone in temperatures below 0°C or higher 40°C. ⚡ Use the original charger (5V/2A or 9V/2A).
Why does the phone turn off at 20 to 30% charge?
This is a typical symptom of improper calibration of the power controller or severe battery wear. Try: Fully discharge the phone before shutdown. Charge to 100% without interruption (at least 3 hours). Repeat the cycle 2-3 times. If the problem persists, replace the battery. Calibration only helps with software failures, not physical wear.
How much does it cost to replace the battery in the Redmi Note 7?
The cost depends on the type of service: 🏠 Official Xiaomi service: 1500-2500 ₽ (6-month warranty). 🔧 Informal workshops: 800-1500 ₽ (1-3 month guarantee). 🛒 Self-sustained replacement: 500–1000 ₽ (The original battery articulated battery: MBJ406740 (4000 mAh, ATL Buy only from trusted sellers - counterfeits can swell in 2-3 months.
Can I use Power Bank to charge if the battery is worn out?
Yes, but with reservations: ✅ Power Bank supports Quick Charge 3.0 (18W) and has overheating protection. ❌ You can't use cheap Chinese power banks without certification, because they can produce unstable voltages that will accelerate wear. 65W. Charge your phone to 80% and turn it off to reduce battery load.
What is the maximum battery life of the Redmi Note 7?
When properly operated, the Redmi Note 7 battery retains 80% of its capacity after: 📅 2–3 years of active use (500–800 charge cycles). 🔄 4-5 years with a gentle mode (charging up to 80%, rare full discharges). After 3 years, the capacity drops to 60-70% of the original, which leads to a noticeable reduction in battery life. Battery replacement is recommended at a capacity below 2000 mAh (50% of the original).