How to Calibrate Your Battery on Xiaomi with an Engineering Menu: A Complete Guide with Codes and Warnings

Why is battery calibration important for Xiaomi smartphones?

Modern lithium-ion and lithium-polymer batteries in Xiaomi smartphones (including the Redmi, POCO and Mi models) lose their accurate charge level indication over time, due to a discrepancy between the actual battery charge and the data that the power controller records, as a result, you can see a spike in percentage charge (for example, from 30% to 1% per second) or a sudden shutdown of the device at 15-20% of the remaining charge.

Calibration of the battery through the engineering menu is a software reset of the charge counter that helps synchronize the controller readings with the actual state of the battery. Unlike the myths of the "three full charge cycles", this method works at the firmware level and gives a more accurate result. However, improper calibration can aggravate problems or even lead to a system failure. Next, we will analyze when the procedure is really needed and when standard methods are enough.

When do I need to calibrate the battery through the engineering menu?

Not all battery problems require engineering intervention, but here are the signs that calibration is warranted:

• 🔋 The smartphone suddenly shuts down when 10-30% although previously working before 1-5%.
• 📉 The percentage of charge "jumps" (for example, from 45% to 20% after rebooting).
• ⚡ After full charging, the indicator shows less than 100% (for example, 95% or 98%).
• 🔄 The battery is discharged unevenly: the first 50% go away in an hour, and the last 20% stay a day.

If your Xiaomi simply runs out quickly due to battery wear (for example, after 2-3 years of use), calibration will not help, in which case you need to replace the battery or optimize the background energy consumption.

• 📱 New phone (less than 3 months of use).
• 🔌 Problems arose after the update MIUI (It is often a firmware bug, not a battery).
• 🔥 The device overheats when charging (this indicates a faulty controller or battery).

Preparation for calibration: what to do before entering the engineering menu

Before you start the procedure, follow the mandatory steps to avoid failures:

1. Completely drain the battery before the device automatically shuts down. Don't use the phone manually before it turns off -- wait until it turns off at 0-1%.
2. Charge your smartphone to 100% without interruption. Use the original Xiaomi charger (or Quick Charge certified).
3. Reboot the device after full charge, and this will reset the system cache and prepare the power controller.

Also consider:

• 🔌 Do not use wireless charging – it can give inaccurate current data.
• 📴 Turn it off. USB-debug OEM-Unlocking in the developer settings (if they were enabled).
• 📡 Turn off Wi-Fi, mobile data and Bluetooth while calibrating.

Discharge the phone to 0% (automatic shutdown)|Charge to 100% without interruption|Reboot the device after charging|Disable all wireless connections|Use the original charger-->

⚠️ Note: If your Xiaomi is equipped with a battery capacity of more 5000 mAh (e.g. mAh, POCO M3, Redmi Note 11 Pro+), The full discharge-charging cycle may take up to 6-8 Don't interrupt the process, it will lead to inaccurate calibration data.

How to enter the engineering menu on Xiaomi: step-by-step instructions

The Engineering Menu (or Engineer Mode) is hidden from the general public because it is designed for service centers, and to get there, use one of the proven methods:

Method 1: Through the code set (for most models)

1. Open the Phone app.
2. Enter the combination: ##4636##
3. In the menu that appears, select Battery Information.

Method 2: Through settings (for MIUI 12 and later)

1. Go to Settings. → The phone.
2. Click 7 times in a row on the MIUI version to activate Developer Mode.
3. Back to Settings → Additionally. → For developers.
4. Activate the Engineering Menu switch (if any).

On some models (e.g. Xiaomi 12T, Redmi K50) the engineering menu may be blocked.

##36446337##

Calibration of the battery through the engineering menu: step-by-step process

After entering the engineering menu, follow the instructions in strict order, and errors at this stage can lead to a reset or incorrect operation of the power controller.

1. Go to Battery Information, and you can see the current parameters: Level, Voltage, Temperature.
2. Click on Battery Calibration (or Reset Battery Stats). On some models, this item may be called Battery Health.
3. Enter the confirmation code: 3845 This is the standard code for resetting battery statistics on most Xiaomi devices.
4. Wait until the process is complete. The phone can reboot automatically. If it's not, do it manually.

After calibration:

• 🔋 Re-discharge and charge the phone completely (1 cycle).
• 📊 Check the readings in Settings → Battery – the discharge schedule should become smooth.
• 🔄 If the problem persists, repeat the calibration through 2-3 no more than a day!).

💡

If after calibration, the phone starts to run out faster, it's a temporary effect. The controller learns to track the capacity again. Give 2-3 charging cycles to stabilize.

⚠️ Note: On devices with Qualcomm Snapdragon chipsets (for example, Xiaomi 12 Pro, POCO F4) Resetting battery statistics can lead to a temporary increase in energy consumption on the first day.

Frequent Mistakes and How to Avoid Them

Even experienced users make calibration errors, and here are the most common ones and ways to prevent them:

• ❌ Interrupt the charging process. If you turn off the charger to 100%, the controller will record the wrong data. Always wait for full charging (the indicator should show 100% and Charging is complete).
• ❌ Use of non-original chargers. Cheap chargers can give unstable voltages, which distorts calibration data. Use only certified accessories.
• ❌ Calibration on cold or overheated phone: Optimal battery temperature for the procedure — 20-25°C. Pri. <10°C or >40°C. The controller can block the data recording.
• ❌ Resetting statistics without a full discharge-charging cycle, if you don't discharge the phone to 0% before calibrating, the new data will be written on top of the old data, which will exacerbate the problem.

On Xiaomi models with a battery capacity of 6000 mAh and above (for example, the Redmi Note 12 Explorer), calibration can take up to 12 hours due to the slow charging cycle of the last 20%.

💡

Calibration is not a panacea; if the battery is physically worn out (capacity has dropped below 70%), the procedure will have a temporary effect, but will not restore the original performance.

Alternative Calibration Methods Without Engineering Menu

If the engineering menu is not available or you are afraid to interfere with the settings, try these methods:

Method 1: Through MIUI Charging Modes

Some MIUI firmwares have built-in battery optimization tools:

1. Go to Settings → Battery → Charging modes.
2. Select Optimized Charging and turn it off.
3. Completely discharge and charge the phone 2 times in a row.

Method 2: With the help of ADB-Teams (for advanced users)

If you have access to ADB, do:

adb shell dumpsys battery reset

Add shell dumpsy battery set level 100

Method 3: Calibration applications

Google Play has utilities like Battery Calibration or AccuBattery, but they are less effective than the engineering menu because they don’t have access to low-level controller settings.

⚠️ Note: Battery calibration applications often request rights SU (Root access is not secure and may take away your warranty, only use them if other methods have not worked.

FAQ: Answers to Frequent Questions About Xiaomi Battery Calibration