Xiaomi Redmi Note 8 phone has become rapidly discharged: what to do in 2026?

Xiaomi Redmi Note 8

If your Redmi Note 8 is gluttonous, don't rush to the service center. 80 percent of the time, you can fix it yourself, from optimizing settings to replacing batteries. In this article, we'll look at all the possible causes of rapid discharge and give you step-by-step instructions to fix them. And you'll learn how to extend the life of the battery by 20-30 percent without drastic measures.

First, let's define what counts as "normal" charge consumption. The new Redmi Note 8 with a battery capacity of 4000 mAh in medium use (social networks, messengers, 2-3 hours of screen time) should hold a charge of 1.5-2 days. If the phone discharges in 6-8 hours at minimum load is a reason to sound the alarm. But before you panic, check a few key points.

1.Diagnostics: how to understand what exactly "eats" the battery

Before we take action, we need to identify the culprit behind high power consumption, and MIUI has built-in tools for analyzing charge consumption, but they don't always show the full picture.

Open Settings → Battery and Performance → Battery Use. Here you will see a discharge schedule and a list of applications ordered by consumption level.

• 📱 Screen – if it takes more than 30% of the flow rate, then the brightness is too high or the display time exceeds the norm.
• 📶 Mobile network/Wi-Fi — Higher expenditure (more) 15%) indicates a poor signal or background activity of applications.
• 🔄 Android System – If the system consumes more than 20%, it may indicate a malfunction MIUI background.
• 🎮 Games/social networks – individual applications should not be eaten by others 10-12% cycle-charge.

If there is no clear leader on the list, but the battery still goes down quickly, the problem may be in the background or hardware wear. For more detailed analysis, use third-party utilities like AccuBattery or GSam Battery Monitor to show the real battery capacity (if it falls below 70% of its face value, it’s time to think about replacing) and identify “vulnerable” services that do not appear in the standard settings.

Note the battery temperature in these applications. If it's consistently above 35-40°C, it's a critical signal: either the battery is worn out or the phone is overheated due to charge or load.

Programmatic reasons: optimization of MIUI and applications

Most of the time, fast discharge is not about hardware, but about incorrect settings or background activity of applications, and let's start with the simplest and most effective ways.

Turn off the auto-run of unnecessary applications. Many programs (especially social networks and instant messengers) run automatically and consume charge even when you are not using them.

1. Go to Settings → Applications → Application Management.
2. Select an app (like Facebook or TikTok) and tap on AutoRun.
3. Turn off the Allow Auto Start option.

Limit background activity. MIUI has a Background Limitation feature that forces applications to close once they are out:

• 🔋 Go to Settings. → Battery and productivity → Battery consumption management.
• 📱 Select Background Limitation and add the most “gluttonous” apps to the list.
• ⚡ Enable the option of Deep Optimization for maximum limitation.

Also check geolocation and notifications. Many applications (like Google Maps or Yandex.Maps) are constantly using GPS even when they are folded. Turn off geolocation for unnecessary services in Settings → Privacy → Permissions → Geodata.

Disable Auto-Run for 5+ applications |

Set background limit for messengers |

Disable geolocation for unnecessary applications |

Turn on dark theme and adaptive brightness |

Virus testing (via Security or Malwarebytes)-->

3. Battery calibration: When the phone "lies" about interest

Sometimes the problem isn't with the battery itself, but with the battery displaying the charge level incorrectly, like the phone showing 30 percent, and then 5 minutes later it suddenly shuts down, because the battery controller is out of action, and the solution is calibration.

Method 1: Manual calibration (without root rights):

1. Discharge the phone before automatically switching off (0%).
2. Connect the original charger and charge for at least 8 hours without interruption.
3. Turn off the charging, turn on the phone and wait for the system to fully boot.
4. Repeat the discharge/charging cycle again.

Method 2: Reset the battery data via the engineering menu (takes care!):

1. Open the Phone app and type ##4636##.
2. Go to the section Information about the battery.
3. Click Reset Battery Statistics (if the option is active).

Attention! Don't use the Google Play "quick calibration" apps, they're either useless or harmful. The only reliable way is with the manual procedure described above.

Hardware problems: battery wear and malfunction

If software methods don't work, the reason lies in the hardware: the average battery life of the Redmi Note 8 is 2-3 years (or 300-500 charge cycles), then the capacity drops by 20-40%, and the phone starts to discharge 2-3 times faster.

How to check the wear of the battery:

• 📊 Install the AccuBattery app and check the Battery Health section. 2500-2800 mAh (originally) 4000 mAh), the battery is critically worn out.
• 🔋 Battery bloating – if the back cover of the phone starts to “sulk” or the screen rises, immediately turn off the phone and do not use it.
• ⚡ Check the charger and cable. Unoriginal accessories can damage the power controller.

If the battery is worn out, it needs to be replaced. The cost of a new battery for the Redmi Note 8 in 2026 is 800-1500 rubles (depending on quality), you can do it yourself, but if you are not sure about your skills, you better contact the service.

Signs of failure of the power controller:

The phone does not turn on without a connected charger.

The swelling is in the process (it stops and goes).

- The battery is discharged to 0% in 10-15 minutes.

In this case, a diagnosis is required at the service center.

💡

If you decide to replace the battery yourself, buy only original Xiaomi-branded batteries or certified counterparts (e.g., from Baseus or Remax). Cheap fakes can swell or ignite!

5 Updates and firmware: how MIUI affects autonomy

Xiaomi regularly releases updates for the Redmi Note 8, but not all of them are optimized for battery saving.For example, after upgrading to MIUI 12.5, many users complained about increased battery consumption due to new animations and background processes.

What to do if the problem occurs after the update:

1. Check out the MIUI version in Settings → About Phone. If it's MIUI 13/14, try rolling back on MIUI 12.0.3.0 - it's considered the most stable version for the Redmi Note 8.
2. Turn off automatic updates in Settings → About Phone → System Update.
3. Reset the settings to factory (don't forget to back up!) This helps in 60% of crashes after updates.

If you don’t want to roll back, try alternative firmware like LineageOS or Pixel Experience. These are often better optimized for battery savings, but require unlocking the bootloader and fastboot skills.

Attention! Custom firmware installation will void the warranty (if it still works) and may lead to a phone blink.

6. Additional tips: how to extend the life of the battery

Even if you have eliminated the root cause of a quick discharge, follow these guidelines to avoid repeated problems:

Proper charging:

• 🔌 Use only an original or certified charger (5V/2A or 9V/2A).
• 🔋 Don't unload the phone before 0% and don't hold on to charging any more 8 The optimal range — 20-80%.
• ⚡ Turn off fast charging if you don’t rush: it wears the battery harder.

Screen settings:

Set a dark theme (in Settings → Screen).

Reduce the lock time to 15-30 seconds.

Turn off adaptive brightness and set the value manually (optimally 40-50%).

Network and connections:

In places with a bad signal (metro, basement), switch to 2G or aircraft mode.

Turn off Wi-Fi and Bluetooth if you are not using them.

Deactivate NFC and Hot Spot in the settings.

Background processes:

Disable sync for unnecessary accounts (Google, Mi Account).

Remove or freeze (via ADB) pre-installed apps (Mi Video, Mi Music, Browser).

Use green mode in Settings → Battery → Power modes.

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If you're monitoring the battery from day one, it's going to be at least 80 percent of its value in 2 years, and the key is to avoid overheating, deep discharges, and cheap charging.

7. When is it time to bring the phone to the service?

If you’ve tried all of these, but the Redmi Note 8 still runs out in a few hours, it’s time to call in the experts.

Symptoms:

• 🔥 The phone is overheated even without load (above 45).°C).
• 💥 Battery swelled (seemingly by deformation of the body).
• ⚡ Charging is not going or is going jerky.
• 📉 Battery capacity on AccuBattery below 2000 mAh.
• 🔄 The phone is spontaneously turned off when 20-30% charge.

In these cases, self-repair can aggravate the problem. Contact an authorized Xiaomi service center or a proven workshop. The average cost of diagnosis is 300-500 rubles, replacing the battery is 1000-2000 rubles (with work).

Attention! If you notice a bloating battery, don't try to charge the phone or put it in your pocket. The battery may ignite! Disable the device immediately and remove the battery (if possible).

FAQ: Answers to Frequent Questions