Battery is one of the most vulnerable components of the smartphone Xiaomi Redmi Note 8T, And that's when you lose capacity over time, and it discharges faster, if your machine turns off when you're in the middle of a shutdown. 20-30% If you're charging, overheating while charging, or running out in a few hours on standby, these are obvious signs of battery wear, but how do you know exactly what's going on without taking your phone apart?
In this article, you will find 7 proven ways to diagnose a battery, from hidden engineering codes to professional applications. 8T, How to interpret data and what to do if the battery is already dead. All methods work without root rights and require no special skills.
Important: Redmi Note 8T equipped with a lithium-polymer battery capacity 4000 mAh (typical) with fast charging support 18W. Average life of such a battery — 300-500 You have full charging cycles, and then the capacity starts to drop, if your phone is older. 2-3 In the past, battery testing has become a mandatory procedure.
1. Checking through hidden engineering code ##4636##
The fastest way to get basic battery information is to use Android’s built-in engineering menu, which requires no additional apps and works on all Xiaomi smartphones, including the Redmi Note. 8T.
To open the menu:
- Open the application "Phone" (keyboard set).
- Enter the combination: ##4636###.
- In the window that appears, select Battery Information.
In this section you are interested in the following parameters:
- 🔋 Level of charge (level) - current percentage of charge.
- 🔌 Power source – Must be Battery (unless the phone is charging).
- ⚡ Voltage is the norm for the Redmi Note 8T 3.7-4.3 V. If the value is below 3.5 V at 100% charge, the battery is severely worn out.
- 🌡️ Temperature - optimally 20-45°C. Exceeding 50°C says overheating.
- 📊 Health status – can be displayed as Good, Unknown or Dead.
⚠️ Note: If Unknown is displayed in the Health Condition**, it does not always mean a malfunction. MIUI This setting is simply not supported.
This method only gives surface information, and deep diagnostics will require specialized applications or hardware tests.
2.Use of the AccuBattery application: detailed wear analysis
AccuBattery is one of the best Android battery monitoring apps, not only showing current capacity, but also tracking charging cycles, temperature and wear rate. It's free (with ads), but it'll require a premium version to be fully functional.
To check the Redmi Note battery 8T via AccuBattery:
In this section, pay attention to:
- 📉 Estimated capacity: Compare it to the factory capacity of 4,000 mAh, and if it's below 3,000 mAh, it's time to change the battery.
- 🔄 Number of charging cycles - the more, the stronger the wear.
- 📈 Wear graph shows how quickly the battery is degrading.
Critical value of wear for Redmi Note 8T — loss 30% capacity (i.e. less than 2800 With this wear, the phone can turn off when 20-30% the charge, and the working time is reduced in 1.5–2 once.
Disable battery optimization for the application|Charge the phone before 100% discharged 0% (1 cycle)|Do not use your phone during the test|Repeat the cycle 2-3 time-in-time-->
3. Testing with Mi Fit or Xiaomi Service: Official Methods
Xiaomi provides two official ways to check the battery: through the Mi Fit application. MIUI) The first method is suitable for self-diagnosis, the second is for professional evaluation.
Method 1: Mi Fit (only for the purpose of MIUI 12 and newer)
- Install Mi Fit and log in.
- Connect the Redmi Note 8T to the Mi Account.
- Go to Profile. → Devices → Your smartphone → Battery status.
This shows the approximate wear rate, but this method doesn't work on all firmware and may not show accurate data.
Method 2: Xiaomi Service (Accurate Diagnostics)
If you need 100% accurate battery information, contact Xiaomi Service Center. wizards use special equipment (Battery Tester) to check:
- 🔋 Real capacity (in mAh).
- 🔌 Internal resistance (norm - up to 200 mOhm).
- 📊 Number of charge cycles.
The cost of diagnosis is free if the phone is warranty. Outside the guarantee, the price is 300-500 rubles.
⚠️ Note: Unofficial service centers can use cheap testers that give an error of up to 15.
4. Verification through ADB: power-user
If you are familiar with the command line, you can get detailed information about the battery through the ADB (Android Debug Bridge: This method requires you to connect your phone to your computer, but it gives you the most accurate data.
Instructions:
- Install. ADB-PC drivers.
- Turn on "Debugging by" USB»** on the phone: Settings → The phone. → Version. MIUI (Press 7 times to activate Developer Mode, then Settings → Additionally. → For developers → Debugging by USB.
- Connect the Redmi Note 8T Enter the command line: adb shell dumpsys battery
In conclusion, pay attention to the following parameters:
| Parameter | Norm for Redmi Note 8T | What does deviation mean? |
|---|---|---|
| level | 0–100 | Current charge in percentage. |
| voltage | 3700–4300 mV | Below 3500 mV at 100% - critical wear. |
| temperature | 200–450 (×0.1°C) | Over 500, overheating. |
| charge counter | ≈4000 (mAh) | Less than 3,000, the battery is worn out. |
| health | 2 (good) | 3 - cold, 4 - overheating, 7 - malfunction. |
If the health parameter is 7, the battery needs to be replaced immediately – further use can lead to bloating or short circuit.
5. Visual examination: signs of bloating and damage
Sometimes you can tell the state of the battery without software, by the outside. 8T for the following symptoms:
Signs of battery bloating:
- 📱 The screen or back cover bent outwards (especially noticeable if you put the phone on a flat surface and sway).
- 🔊 There are gaps between the body and the screen.
- 🔋 The phone does not stay on a flat surface (swings like a swing).
- 🔌 The charging cable is poorly inserted into the connector (the battery presses on the port).
Other visual defects:
- 🔥 The appearance of foreign smells (gas, chemical smell).
- 💧 Leaking electrolyte (white plaque on the board or under the cover).
- 🔌 Overheating of the body in the battery area (even without load).
⚠️ Warning: If you find battery bloating, immediately turn off your phone and do not use it until battery replacement.Lithium polymer batteries can ignite or explode when bloated!
To check, you can carefully remove the back cover (if you have experience disassembling phones), a normal battery should be flat, without bulges, if it is swelling, it should be replaced within 24 hours.
What to do if the battery is blown?
6. The discharge test: how to determine the real capacity
One of the most reliable ways to test battery capacity is through a controlled discharge test, and you’ll need a fully charged phone and monitoring app (like the GSam Battery Monitor).
Instructions:
- Charge the Redmi Note 8T 100%.
- Turn off all background processes (turn on Flight mode).
- Run the test: Turn on the YouTube video at maximum brightness and volume.
- Take a look at the time it takes for the phone to run down to 0%.
Compare the result to the norm:
| Battery status | Discharge time (video, max brightness) | Exemplary capacity |
|---|---|---|
| New battery | 5-6 hours | 3800-4,000 mAh |
| Average wear (10-20%) | 4-5 hours | 3200-3600 mAh |
| Strong wear (30–50%) | 2-3 hours | 2000-2800 mAh |
| Critical wear (>50%) | <2 hours | <2000 mic |
If the phone is discharged in less than 3 hours, the battery needs to be replaced.
- 📱 Ambient temperature (in cold, the battery goes down faster).
- 🔄 The firmware version (on MIUI 13/14 Optimization is better than MIUI 11).
- 🔌 Quality of charger (cheap cables accelerate wear).
💡
For a more accurate test, use No Sound mode and turn off mobile data, which will eliminate the influence of background processes.
Verification through the annex CPU-Z: alternative
CPU-Z — It's a popular iron diagnostics app that also shows battery information, which is less accurate than AccuBattery, but doesn't require long tests.
How to use:
- Set CPU-Z.
- Go to the Battery tab.
- Pay attention to Level, Voltage and Temperature.
The following data are useful in this annex:
- 🔋 Charge level in mV - compare with the table of voltages: Charge (%) Voltage (B) 100% 4.2-4.3 50% 3.7-3.8 20% 3.4-3.5 0% 3.0-3.2
- 📊 Discharge schedule – if voltage drops too quickly, battery is worn out.
CPU-Z It doesn't show the capacity in mAh, but it helps you track the abnormalities in the battery, for example, if you have a voltage below 3.6 V at 50% charge, it's a sign of extreme wear and tear.
💡
A voltage below 3.4 V at 20% charge is a critical signal, in which case the battery can shut down at 15-30% and needs to be replaced.
What to do if the battery is worn out?
If the diagnosis showed that the battery Redmi Note 8T You are over 30% exhausted and have three options:
1. Battery replacement at the service center
- ✅ Pros: original battery, 6-12 months warranty.
- ❌ Cons: cost 1500-2500 rubles (depending on the region).
2. Self-substitution
- ✅ Pros: cheaper (battery costs 800-1200 rubles).
- ❌ Cons: risk of damage to plumes or display, loss of warranty.
3. Optimization of the phone (if the wear is not critical)
- 🔋 Turn off the background activity of applications.
- 📱 Use dark themes (AMOLED-screen consumes less energy).
- 🔌 Charge your phone to 80% (this reduces wear and tear).
- 🌡️ Avoid overheating (do not play games on charging).
⚠️ Warning: When you replace your battery yourself, use only original or certified batteries. Cheap alternatives can not only fail quickly, but also cause fires!
If you’re considering replacing your battery, check out the Redmi Note video manual. 8T (You can do this on YouTube:
- 🔧 Plastic blades for opening the body.
- 🔥 Hair dryer or glue heating station.
- ⚡ New battery (article: MBJ404748 for the original battery).