Calibration of the Xiaomi Redmi Note 5 battery: myths and real methods of restoring charge accuracy

Owners of Xiaomi Redmi Note 5 (codenamed whyred) often face the problem when the smartphone suddenly turns off at 20-30% charge or, conversely, shows 100%, but after 5 minutes it is discharged to 80%.

The calibration process does not require disassembling the phone or special equipment, but its effectiveness depends on the correctness of the steps. In this article, we will discuss the official method from Xiaomi, alternative methods (including the use of the same method). ADB), We also explain why some “people’s” tips (for example, charging) 12 Not only are they useless, they're also harmful to lithium polymer batteries. 5 It quickly disintegrated after updating to MIUI 12/13 Replace your battery, this guide is for you.

⚠️ Critical warning: Calibration does not restore the capacity of the worn-out battery! 2-3 When you use it for hours or when you're using it normally, or when you're charging it, you need a physical replacement, and calibration only helps if the charge controller malfunctions when the indicator is incorrect.

Once every 3 months | Only after a battery change | Never done | When a charge problem starts-->

1. When does the battery calibration really need to be done?

Many users confuse the natural wear of the battery with the need for calibration. Before proceeding with the procedure, check whether your situation applies to the following cases:

  • 📉 The phone turns off when 15-30% although it had previously been used before 1-5%.
  • 🔋 After full charging, the indicator shows 100%, through 10-15 minutes of use falls to 80-85%.
  • 🔄 The percentage of charge "jumps" (for example, from 45% to 20% after rebooting).
  • 🔌 After replacing the battery (even the original) the phone shows an incorrect charge level.

If one of these is the right one, calibration can help, but there are also false symptoms that can't help.

  • ⏳ The battery is discharged for 3-4 an hour of active use (this is a sign of wear and tear, not a failure of the controller).
  • 🔥 The phone warms up while charging or playing (a problem with the board or battery).
  • 📴 The smartphone does not turn on after full discharge (possibly a deep discharge damaged the battery).

💡 How to check the wear of the battery?

Type in the phone app code ##4636##, go to the Battery Information menu and compare the Battery Health setting. If below 80%, calibration won't help, you need a replacement.

💡

Before calibrating, update the firmware to the latest version of MIUI. Older versions (below MIUI 11) had charge display bugs that were fixed in new builds.

2. Official calibration method from Xiaomi (without ROOT)

This is a method that works for the Redmi Note 5 on any version of MIUI and does not require superuser rights. It is based on a full discharge/charging cycle that resets statistics in the batterystats.bin file.

Step-by-step:

  1. Discharge your phone before automatically shutting down. 📵 Use your phone normally until it turns off. ⚠️ Wait at least 30 minutes - it's important to reset the controller.
  2. Charge the phone before 100% switched off. 🔌 Connect the original charger (5V/2A) And wait for the green light. ⏳ Leave it on the charger for more. 1-2 hour 100%.

Use the original cable and charger|Disable all backgrounds (Wi-Fi, Bluetooth, mobile data)|Do not interrupt the charging/discharge process|Repeat the cycle 2 times in a row-->

⚠️ Note: If the problem persists after calibration, the cause may be:

  • 🔋 Non-original battery (Chinese "originals" often don't have the right controller).
  • 📱 Damaged charging connector or power controller on motherboard.
  • 🤖 Failure in firmware (try resetting to factory settings via Settings) → The phone. → Resetting settings).

Alternative method: calibration via ADB (for advanced)

If the standard method didn’t work, you can reset battery statistics via Android Debug Bridge (ADB), a method that requires a computer and minimal command line knowledge.

What you need:

    Instructions:

    1. Connect the phone to the PC and confirm the debugging permission.
    2. Open the command line (Win + R → cmd) and type in: adb shell su rm /data/system/batterystats.bin reboot
    3. After rebooting, complete the full discharge/charging cycle (as in the official method).

    ⚠️ Attention: Su commands require ROOT-If you don't have them, use an alternative command without su (but the effectiveness is lower):

    adb shell dumpsys battery reset
    What if the ADB can’t see the device?
    1. Check if debugging is included on USB 2. Install Xiaomi drivers from the official website (section "Mi Unlock"). 3. Try another one. USB-cable (original better). 4 Restart your phone and PC. 5 If you use Windows, run the command prompt on behalf of the administrator.

    You can find dozens of calibration tips online, most of which are not only useless, but also harmful.

    MythReality.Effects of consequences
    You need to charge your phone for 12 hours.Lithium polymer batteries have no memory effect. Prolonged charging only accelerates wear and tear.Overheating, reducing capacity by 5-10% per year.
    "Calibration restores capacity."The procedure only resets the controller data, but does not repair the battery.False confidence in the performance of the worn-out battery.
    You need to discharge your phone to 0% every month.Deep discharge (below 3%) damages the battery, and the optimal range is 20-80%.Reduced service life by 20-30%.
    “Accumbattery calibration applications work.”Applications only show statistics, but cannot physically affect the controller.A waste of time and resources on the phone.

    💡 Expert commentary:

    Battery manufacturers (such as ATL or Samsung SDI, which supply batteries for Xiaomi) strongly recommend against allowing a discharge below 3% or a charge above 90% to extend the lifespan.

    5. What to do if calibration does not help?

    If after 2-3 cycles of discharge / charging the problem remains, the causes may be deeper:

    • 🔋 Battery wear: Check capacity through the app CPU-Z or AIDA64. If the real capacity is below 70% of the face value (3300 mAh for Redmi Note 5), you need a replacement.
    • 📱 Power controller issues: If the phone doesn't hold charge even with a new battery, the chip may have been damaged PMIC (For example, Qualcomm PMI8998 Snapdragon 636).
    • 🤖 Firmware failure: Try flashing your phone through the Mi Flash Tool with a clean all option (erase all data!).

    ⚠️ Note: If you decide to replace the battery, buy only original batteries with the label:

    • Xiaomi BM43 (3300 mAh) – for the global version.
    • Xiaomi BM44 (4000 mAh) – for the Chinese version (Redmi Note 5 Pro).

    Counterfeit products often have an understated capacity (2000-2500 mAh) and can damage the phone.

    1. Correct connection of the battery plume (don’t confuse polarity!).

    2. the integrity of the contacts on the motherboard (often oxidized).

    3. Compatibility of the new battery controller with your model.-->

    6.How to extend the life of the battery after calibration?

    To keep calibration results longer, follow these guidelines:

    • 🔌 Use the original chargers (5V/2A or 9V/2A Quick Charge Supported 3.0). Cheap charging with AliExpress often gives unstable voltage.
    • 🌡️ Avoid overheating: Do not play heavy games while charging and do not leave your phone in direct sunlight.
    • 📴 Don't discharge until 0%: Optimal range — 20-80%. You can use applications like AccuBattery (monitoring only) to do this!).
    • ⚡ Turn off fast charging if you are not in a hurry: go to Settings → Battery → Quick charging and deactivate the option.

    📊 Wear statistics:

    According to Battery University research, if these rules are met, the Redmi Note 5 battery will last:

    • ✅ 400-500 cycles (about) 2 years) when charged 0-100%.
    • ✅ 800-1000 cycle (3-4 year) when charged 20-80%.

    FAQ: Frequent questions about battery calibration

    ❓ Can the battery be calibrated without fully discharging?
    No. To reset the statistics, the controller must record a full discharge (0%) and a full charge (100%).
    ❓ Why the phone started to discharge faster after calibration?
    The battery is probably worn out, and the calibration just showed the actual capacity. Check the battery's health using ##4636## or replace it.
    ❓ Should I calibrate a new battery after replacement?
    Yes, but only once. A new battery may be showing an incorrect charge due to the lack of cycle history in the system.
    ❓ Can calibration damage the phone?
    The procedure itself is safe, but if you interrupt the charging / discharging cycle or use a faulty charger, there may be failures in the operation of the controller.
    ❓ How long does it take to complete calibration?
    4 to 6 hours: ~2 hours to discharge + 2-3 hours to charge + 1 hour to stabilize after switching on.