Xiaomi’s Battery Checker: A Complete Guide to Hidden Codes and Tests

The battery is the heart of your Xiaomi smartphone, which not only affects battery life, but also the stability of the device. Over time, the battery capacity inevitably decreases: after 300-500 charging cycles, it can lose up to 30-40% of its original capacity. But how do you know that the problem is in the battery, and not in software failures or the background of running applications?

In this article, we’ll look at 5 proven ways to diagnose the battery on Xiaomi, Redmi and POCO phones, from hidden engineering menus to third-party apps. You’ll learn how to check the actual capacity, discharging speed, temperature and even the state of the charging controller without disassembling the device.

⚠️ Important: Some methods require access to an engineering menu or install additional apps. If your phone is warranty, avoid methods that require unlocking the bootloader or root rights - this may void the Xiaomi warranty.

The fastest way to get basic information about the battery is to use a hidden service code.It works on most Xiaomi smartphones, including the Redmi Note 10/11/12, POCO F3/F4/F5, Mi 11/12/13 and others based on Android 10+.

Instructions:

Open the Phone app.
Enter the combination: ##4636## (without pressing the call button).
In the menu that appears, select Battery Information.

Here you will see the key parameters:

🔋 Level of charge (level) – current percentage in digital form (may differ from the one displayed on the screen).
🌡️ Temperature - optimal range: 20-40°C. If the value is greater than 45°C in normal use is a sign of overheating or battery degradation.
⚡ Voltage: Normal for lithium polymer batteries: 3.7-4.2 V at 100% charge. If the voltage is below 3.5 V at 20% charge, the battery is severely worn out.
📊 Health - shows Good (good), Unknown (undefined) or Dead (faulty) and new phones may show as Unknown - that's OK.

⚠️ Note: If the #4636## menu does not have the Battery information tab, then the manufacturer has blocked access.

📊 How often do you check the battery status?

Once a month

Only when problems arise

Never checked.

I don't know how to do that.

Diagnostics through the Safety Annex (MIUI 12/13/14)

MIUI has a built-in battery monitoring tool that many users overlook, which allows you to see real screen time, application charge consumption, and even battery health.

How to open it:

Go to Settings → Battery and Performance.
Slap the icon. ⚙️ (Battery settings) in upper right corner.
Select Battery Health (Battery Health) status.

What can I find out:

📉 Battery capacity – comparison of current capacity with factory capacity (e.g., 4,000 mAh/4500 mAh means 11 times wear and tear%).
🔄 Number of charging cycles – after 500 cycles, the capacity usually drops to 70-80% of the original.
⏱️ Full charge time – if it doubles compared to the new phone, the battery degrades.
🛑 Warnings – for example, high temperature when charging or battery requires replacement.

💡

If your phone doesn’t have Battery Status, upgrade to the latest version of MIUI. Older versions (before MIUI 12) may not have this feature.

🔍 How do you interpret the data? If the battery capacity has dropped below 80% of the factory capacity, it is recommended to replace it. For example, for the Redmi Note 10 Pro with the original 5020 mAh, the critical value is 4000 mAh.

Xiaomi smartphones on MediaTek chipsets (e.g. Redmi 9/9A/9C, POCO M3/M4) have an extended engineering menu where you can check the battery in more detail, including internal resistance and charging/discharge current.

Instructions:

Open the Phone app.
Enter the code: ##36446337## (or #3644633## for older models).
Go to the Battery tab.

Key parameters in the menu:

Parameter	Normal value.	What does deviation mean?
Battery Voltage (mV)	3700–4200 mV	Below 3500 mV at 20% charge - critical wear
Battery Temperature (°C)	20–40°C	Above 45 ° C - overheating, risk of bloating
Battery Capacity (mAh)	≥80% of the factory	Below 70% – Replacement is required
Charging Current (mA)	Corresponds to the power of the RAM (for example, 1800 mA for 18W)	Significantly lower is the problem with the cable, the RAM or the controller

⚠️ Warning: Do not change any settings in the engineering menu unless you are sure of their purpose! incorrect settings can lead to loss of warranty or damage to the phone.

Charge your phone to at least 50%

Disable all background apps

Use the original cable and charger

Do not interrupt the verification process-->

4. Third-party applications for deep diagnostics

If the built-in MIUI tools don't provide enough data, you can use third-party utilities. We tested 3 of the most accurate applications for Xiaomi, which show the real capacity, the number of cycles and even the state of the battery cells.

Top.-3 battery-testing applications:

📊 AccuBattery – analyzes the battery health, shows the real capacity and discharge rate. Plus: runs without root, minus: requires calibration (2-3 charging cycles).
🔍 CPU-Z — Battery displays voltage, temperature and condition, plus: no adjustment, minus: no wear data.
🛠️ AIDA64 — Professional tool with detailed information about the battery controller (Li-Po/Li-Ion), minus: complex interface.

How to use AccuBattery (Step-by-step):

Install the app from Google Play.
Charge your phone to 100% and calibrate (follow the instructions in the app).
Use your phone as usual for 1-2 days.
Go to the Health tab – the real capacity and the percentage of wear will be displayed here.

Critical value in AccuBattery: if the Health score is less than 80%, the battery needs to be replaced soon – further operation can lead to a sudden shutdown of the phone even at 30-40% charge.

Why does AccuBattery show a capacity smaller than the factory?

This is OK! The app takes into account real battery wear. For example, if the box says 5,000 mAh and AccuBattery shows 4200 mAh, it means that the battery has lost 16% of capacity. Manufacturers often specify "typical" capacity, rather than minimum, so the difference of 5-10% can even be on a new phone.

5.Discharge test: how to check autonomy manually

If you can't use the apps, you can do a manual discharge test, which helps you identify hidden battery problems that aren't visible in the numbers (such as sudden power drawdowns).

How to run the test:

Charge your phone to 100% and disconnect from the network.
Enable In-plane mode (to eliminate network influence).
Run one resource-intensive application (such as a game or video player) and record the time.
Track your discharge percentage every 15 minutes.

Normal indicators for Xiaomi:

📱 Budget models (Redmi) 9A/10A): 4–5 screen time when actively used.
📱 Mid-size segment (Redmi Note) 11/POCO X4): 6–8 hours.
📱 Flagships (Xiaomi) 13/14): 8–10 hours.

⚠️ Warning: If the phone runs 20 to 30 percent in 30 minutes of standby (without active use), it's a sign of critical battery wear or software failure.

💡

If the phone turns off at 15-20% charge, it’s a sure sign that the battery controller is not calibrating the charge level correctly. Try calibrating the battery (discharge to 0% and charge to 100% without interruption) or replacing the battery.

External signs of battery failure

Sometimes the battery problem is visible to the naked eye.

🔋 Bloating – if the back cover or screen starts to “go away” and the phone gets thicker, immediately turn it off.
🔥 Overheating – if the phone is heated above 45°C in normal charge or use, this is a sign of battery degradation or short circuit.
⚡ Slow charging – if the phone charges 2-3 times longer than before, with the same charger.
🛑 Spontaneous reboots – if the phone turns off at 20–30% charge, it means the battery voltage drops too quickly.

What to do if you find a blistering?

Turn off your phone immediately and don’t turn it on.
Do not leave the device on charge.
Contact the Xiaomi service center or phone repair shop for emergency battery replacement.

🔧 Tip: If you decide to replace the battery yourself, buy only original batteries labeled Xiaomi or certified analogues (for example, from the same battery). ZMI). Cheap fakes can damage the charging controller.

7.When it's time to change the battery: checklist for Xiaomi users

We have collected the main symptoms that indicate that the battery needs to be replaced in the near future:

The phone is discharged by 50% in 1-2 hours in standby mode

Capacity on AccuBattery is below 70% of the factory

Bloating the body or screen retreat

The phone turns off at 20-30% charge

Charging takes more than 4 hours (when using the original RAM)-->

💡 In official service centers Xiaomi price varies from 1,500 to 4000 rubles depending on the model. In informal workshops you can find a replacement cheaper (from 800 rubles), but the risk of running into a poor-quality battery is higher.

If you have experience disassembling phones and special tools (suction cup, mediator, T3/T4 screwdriver), you can try.

⚠️ Risk of damaging plumes or screen.
⚠️ Loss of leakage (relevant for protected phones) IP53/IP68).
⚠️ Cancellation of the guarantee (if it is still valid).

FAQ: Frequent questions about Xiaomi battery check

🔋 Can you restore the battery capacity on Xiaomi?

No, you can't restore a worn-out lithium polymer battery. All the "miracle" methods (deep discharge, low-current charging) are myths. The only way to get back to autonomy is to replace the battery.

📱 Why Xiaomi is 100% charger and your phone is running low?

This is due to the incorrect calibration of the controller. Try: Discharge the phone to 0% (until it turns off); Charge to 100% without interruption (preferably the original RAM); Repeat the cycle 2-3 times; If it does not help, the problem is the wear of the battery.

⚡ Can a fast charger ruin the battery?

Modern Xiaomi smartphones (such as the Redmi Note 12 Pro+ with 120W charging) have built-in overheating protection. However, the constant use of fast charging can accelerate degradation by 10-15%. Optimal option: Use fast charging when you need to urgently charge your phone. For daily charging (at night), use 10W-18W RAM.

🌡️ What is the battery temperature considered normal when charging?

Optimal range: 20-35°C is normal. 35-40°C is acceptable for heavy charging (e.g. 30W+); 45°C is critical! Turn off charging and let the phone cool. If the phone warms even when 10W is charging, check the cable and RAM for damage.

🔄 How many charging cycles can Xiaomi battery withstand?

Average life of lithium polymer batteries: 300-500 cycles to lose 20% capacity, 800-1000 cycles to lose 50% capacity (phone holds charge for 2-3 hours), One cycle = discharge from 100% to 0%. For example, if you discharge the phone from 100% to 50%, and then again to 100% and up to 50%, this is considered a single cycle.