Battery in a smartphone Xiaomi Redmi Note - one of the most vulnerable components. After 2-3 years of intensive use, even the original battery begins to quickly discharge, swell, or turn off at 20-30% charge. If your phone suddenly turns off, overheats while charging, or holds a charge for less than a day, it's time to think about a replacement.

In this article you will find detailed instructions for replacing the battery for all popular models of the series Redmi Note (from Note 3 Pro to Note 12 Pro+), including choosing a compatible battery, necessary tools, and step-by-step disassembly of the case. We will also reveal hidden nuances of calibrating a new battery, which the manufacturer is silent about in official manuals, and we will explain why cheap analogues can reduce the service life of the phone by 40%.

How to understand that the battery Redmi Note needs replacement?

The first signs of battery wear are often attributed to “firmware glitches” or “background processes”. However, if you notice at least 3 symptoms from the list below, the problem is in the battery:

  • 🔋 The phone discharges in 4–6 hours with moderate use (social networks, instant messengers, calls).
  • ⚡ Charging jumps: for example, from 40% it immediately drops to 15%, and then returns back.
  • 🔥 The case heats up in the battery area even without load (especially when charging).
  • 🛑 The smartphone turns off at 20–30% charge and does not turn on without being connected to the network.
  • 📏 Visual bloating: the screen or back cover is raised and warps when pressed.

For accurate diagnostics, check the battery status through the engineering menu or applications like AccuBattery (Android). B AccuBattery pay attention to the parameter "Battery Health" (Health): If it is below 70–75%, the battery is critically worn out. It is also useful to measure battery life in standby mode: OK Redmi Note should stand for at least 12–15 hours without recharging.

⚠️ Attention: If the battery is swollen, don't delay replacement! Lithium-ion batteries in this condition may ignite due to mechanical stress or overheating. It is especially dangerous to continue charging your phone - this increases the risk of a short circuit.

A swollen battery can be identified without disassembling: place the phone face down on a flat surface and lightly press the center of the back cover. If the body “plays” or bends, this is a sure sign of bloating. In such cases do not try to disassemble the phone yourself, if you are inexperienced: a damaged battery may release corrosive gases.

📊 Which Redmi Note model do you have?
  • Redmi Note 8/8 Pro
  • Redmi Note 9/9 Pro
  • Redmi Note 10/10 Pro
  • Redmi Note 11/11 Pro
  • Redmi Note 12/12 Pro
  • Other model

Which battery to choose for Redmi Note: original or analogue?

Spare parts market for Xiaomi is filled with fakes, so choosing a battery is a critical step. Original batteries from Xiaomi are more expensive, but guarantee compatibility with the power controller and long service life. Analogs from trusted brands (for example, Patona or Baseus) may be cheaper, but require careful inspection.

Battery type Pros Cons Average price (2026)
Original (Xiaomi) 100% compatibility, optimal charging current, long service life (500+ cycles). High price, risk of running into a fake (even from official sellers). 1 500–3 000 ₽
Premium analogue (Patona, Baseus) The quality is close to the original, often with improved capacity (+10–15%). May not support fast charging at full power. 1 000–2 000 ₽
Budget analogue (no-name) Low price, fast delivery. Risk of swelling after 3–6 months, unstable operation of the controller. 500–1 200 ₽

When purchasing, pay attention to the following parameters:

  • 🔍 Capacity: must match the original (for example, Redmi Note 10 Pro - 5020 mAh, Note 9 Pro - 5020 mAh, Note 8 Pro - 4500 mAh). Analogs with an overestimated capacity (for example, 6000 mAh instead of 5000) often turn out to be a hoax.
  • 📦 Packaging: original batteries Xiaomi supplied in a white box with a hologram and QR code for authentication. Analogues from Patona have branded blue packaging.
  • 🔧 Connector: must fit perfectly into the connector on the board. Cheap knockoffs often have thinner or narrower contacts, resulting in poor connections.
  • 📅 Production date: Fresh batteries (not older than 6 months) hold a charge longer. The date is indicated on the label in the format YYYY-MM-DD.
⚠️ Attention: Buying a battery at AliExpress or Wildberries, check reviews with photos! Often sellers send batteries without protective film or with damaged contacts. The best option is to order through official distributors Xiaomi (For example, Mi Store) or trusted spare parts stores (FixPriceService, GSMMoscow).

If you choose an analogue, be sure to check with the seller whether it supports fast charging (For example, 33W for Redmi Note 11 Pro). Cheap batteries often limit current to 18W, which increases charging time by 30–40%.

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Before purchasing a battery, check its compatibility with your model through the service GSMArena. Enter the name of the phone in the search and find the "Battery" section - the original capacity and type of battery is indicated there.

Preparing for replacement: tools and safety precautions

Replacing the battery in Redmi Note Requires precision and the right tools. Unlike iPhone, where the battery is glued to the body, in Xiaomi it is fixed with double-sided tape, but this does not make the process easier: one wrong step can damage the cables or the display.

You will need:

  • 🔧 Screwdriver set: cross (PH00) and flat (1.5 mm) for housing screws, as well as a five-pointed (Pentalobe P2) for some models (for example, Redmi Note 9).
  • 🧲 Sucker: for removing the screen (especially important for models with OLED displays, for example, Note 10 Pro).
  • 📏 Plastic spatulas or mediators: for separating the case without scratches.
  • 🔥 Hairdryer or heat platform: to soften the adhesive (temperature 60–70°C).
  • 🧴 Isopropyl alcohol (90%+): To remove residual adhesive.
  • 🔋 New battery with protective film on the contacts.

Also prepare your workplace:

  • ✅ Lighting: bright lamp or table lamp.
  • ✅ Antistatic mat or regular wooden surface (metal can cause short circuits).
  • ✅ Container for screws (for example, a magnetic stand).
⚠️ Attention: Never use metal tools to pry off the battery! Even slight damage to the shell can lead to electrolyte leakage. If the battery is swollen, wear safety glasses and gloves - if punctured, it may shoot out corrosive liquid.

Before starting work turn off your phone completely and remove the SIM card. If the battery is swollen, do not connect your phone to charger - this may cause a short circuit. It is also recommended to remove the case and clean the case from dust to prevent foreign particles from getting inside.

Back up data (photos, contacts, messages)|

Charge the phone to 30–50% (if the battery is not swollen)|

Prepare tools and work area|

Turn off the phone and remove the SIM card|

Wear an antistatic wrist strap (optional) -->

Step-by-step instructions: how to disassemble Redmi Note and replace the battery

The disassembly process varies slightly depending on the model, but the general layout is the same. Below is a universal instruction suitable for most Redmi Note (from Note 7 to Note 12). For accurate information on your model, use iFixit.

Step 1: Removing the back cover

On most models Redmi Note the back cover is glued. To remove it:

  1. Heat the edges of the case with a hairdryer (30-40 seconds on each section).
  2. Insert a plastic spatula into the gap between the lid and the frame (start from the bottom edge where the charging connector is).
  3. Carefully move the spatula around the perimeter, removing the glue. If the lid does not budge, heat it again.

Step 2: Disconnecting the Battery

After removing the cover, you will see the battery covered with black film. First, disconnect the battery connector from the motherboard (usually it is located at the top and marked as BATT). Use a plastic spatula to avoid damaging the contacts.

Step 3: Removing the Old Battery

The battery is glued to the case with double-sided tape. To remove it:

  1. Use a plastic spatula to pry off the battery from any angle.
  2. If the adhesive is too strong, drop isopropyl alcohol under the battery - it will dissolve the adhesive.
  3. Don't pull on the train! Carefully lift the battery until it comes off completely.

Step 4: Install a New Battery

Before installing a new battery:

  • Clean the seat from any remaining adhesive with alcohol.
  • Remove the protective film from the contacts of the new battery.
  • Glue the battery with new double-sided tape (usually included).
  • Connect the connector to the motherboard.

Step 5: Assembling the Phone

Make sure all cables are connected and screws are tightened to the correct torque (do not overtighten!). After assembly, turn on the phone and check:

  • 🔋 Charging is stable (without percentage surges).
  • 📱 The phone does not overheat.
  • 🔌 Fast charging works (if supported).

If the phone does not turn on after replacement, check:

  • Is the battery connector connected correctly?
  • Are the display cables or power buttons damaged?
  • Are there any foreign objects (screws, pieces of tape) left under the battery?
What to do if the phone does not turn on after replacing the battery?

1. **Check the battery connector**: it often comes off during assembly. Gently press it with your finger and try to turn on the phone.

2. **Connect to charge**: If the battery is completely discharged, it may take 5-10 minutes to reach a minimum charge.

3. **Reset settings via Recovery**: hold Power + Volume Up, select Wipe data/factory reset. Attention! This will delete all data.

4. **Check the cables**: if the phone does not respond to buttons, the power button or display cable may have come loose.

5. **Contact service**: if all else fails, the problem may be with the power controller on the motherboard.

Calibrating a new battery: why it is important and how to do it right

Many users miss this step, but calibrating a new battery critical for the correct operation of the power controller. Without it, the phone may show an incorrect charge percentage, quickly discharge, or turn off by 30-40%.

The calibration process takes 2-3 charge/discharge cycles. Here's how to do it:

  1. Full discharge: Use the phone until it turns off automatically (do not recharge!).
  2. Charge up to 100%: Connect the original charger and wait until it is fully charged. Don't interrupt the process!
  3. Additional 2 hours on charge: After reaching 100%, leave the phone connected for another 120 minutes (this will reset the controller’s “memory”).
  4. Repeat the cycle 2-3 times to stabilize the readings.

After calibration, check the actual battery capacity using AccuBattery or engineering menu (*#*#4636#*#* → "Battery information"). Parameter "Wear level" should be close to 0–5%.

⚠️ Attention: Do not use “quick” calibration methods (for example, through the engineering menu MTK Engineer Mode)! They reset the controller data, but do not take into account the actual state of the battery, which can lead to incorrect charge readings.

If after calibration the phone still discharges quickly, check:

  • 🔌 Originality of the charger: Non-original chargers may undercharge the battery.
  • 📱 Background processes: Disable auto-download of unnecessary applications in settings (Settings → Applications → Autorun).
  • 🔄 Software updates: sometimes firmware bugs cause increased battery consumption (check in Settings → About phone → System update).
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Calibrating a new battery takes 2-3 complete charge/discharge cycles. Without it, the power controller may show an incorrect charge percentage, which will lead to sudden shutdowns of the phone.

Common mistakes when replacing a battery and how to avoid them

Even experienced users sometimes make mistakes that shorten the life of a new battery or damage the phone. Here are the most common of them:

  • 🛠️ Using metal tools: Scratches the case and may puncture the battery. Always use plastic spatulas.
  • 🔥 Overheating when removing cover: If you heat the hairdryer for more than 40 seconds in one area, you can melt the glue or damage the cables.
  • 🔌 Battery connector not disconnected: If you forget to disconnect the battery before operation, a short circuit may burn the motherboard.
  • 📦 Saving on glue: If you do not replace the old double-sided tape, the battery will dangle, which will lead to a break in the cable.
  • 🔋 Buying a battery without testing: Counterfeits often have low capacity or do not support fast charging.

Another common mistake is incorrect assembly. For example, if you tighten the screws, you can damage the threads in the case, and if you don’t tighten them enough, the phone will creak. Optimal screw force Redmi Note — 0.3–0.5 Nm (use a torque screwdriver if available).

Also, many people forget about leak testing after assembly. If there are gaps between the case and the screen, dust and moisture will get in there, which will eventually damage the display or motherboard. To check the tightness, lightly press the screen around the perimeter - it should not sag.

💡

If, after replacing the battery, the phone's network reception becomes worse, check the antenna cables (they are located under the metal cover at the top of the case). Perhaps they came off during disassembly.

Should I change the battery myself or contact a service center?

Replacing the battery yourself is cheaper (saving 50-70% compared to a service), but is not suitable for everyone. Assess your skills and risks:

Criterion Self-replacement Contacting service
Cost 500–2000 ₽ (battery + tools) 1500–4000 ₽ (depending on the model)
Time 1–2 hours (with preparation) 1–3 days (including diagnostics)
Warranty No (risk of damage to your phone is yours) Yes (3-12 months labor and parts)
Difficulty Intermediate (electronics skills required) Low (everything will be done for you)
Risks Damage to cables, display, motherboard Use of non-original spare parts (in unofficial services)

You should contact the service if:

  • 🛠️ You have no experience in disassembling phones.
  • 🔧 The battery is swollen (the risk of battery damage is high).
  • 📱 The phone is under warranty (self-repair will void it).
  • ⚡ An urgent replacement is needed (the service will do it in 1-2 hours).

When choosing a service, give preference official partners Xiaomi or a proven workshop with reviews. Avoid salons where:

  • 🚫 They do not provide a guarantee for work.
  • 💰 The price is significantly lower than the market price (a sure sign of non-original spare parts).
  • ⏳ They refuse to show the repair process.

If you decide to change the battery yourself, film the process - this will help you assemble the phone correctly if something goes wrong. Also, keep all screws in separate containers to avoid mixing them up during assembly (in Redmi Note screws of different lengths are used!).

Frequently asked questions (FAQ)

Is it possible to replace the battery in Redmi Note without disconnecting the screen cable?

Technically yes, but it's extremely risky. The display cable is very fragile and can be easily damaged if moved carelessly. If you are not confident in your skills, it is better to disconnect the cable, even if this means removing the metal cover from the motherboard. In models Redmi Note 10/11/12 The screen cable is located under the battery, so it will have to be disconnected in any case.

How long will a new battery last?

The service life depends on the type of battery and operating conditions:

  • Original battery: 500–800 charging cycles (2–3 years with heavy use).
  • High-quality analogue (Patona, Baseus): 400–600 cycles (1.5–2.5 years).
  • Cheap no-name: 200–300 cycles (6–12 months).

To extend battery life, avoid:

  • Charging “up to 100%” (optimally keep the charge at 20–80%).
  • Overheating (do not leave the phone in the sun or near heat sources).
  • Using non-original chargers.
Why did my phone run slower after replacing the battery?

This may be due to several reasons:

  1. Reset settings: if you reset your phone via Recovery, system optimizations could fail. Reboot your device 2-3 times - this will help.
  2. Poor battery contact: Check if the connector is seated tightly. If the contacts are oxidized, clean them with alcohol.
  3. Background calibration: in the first days after replacement, the system may slow down due to re-indexing of files and adaptation to the new battery.
  4. Damage to cables: If during disassembly you touch the cables of the buttons or display, this may cause lags.

If the problem does not go away after 2-3 days, check your phone using CPU-Z for overheating of the processor or lack of RAM.

Can I use a battery from another model? Redmi Note?

No, even if the capacity and dimensions are the same. Each model Redmi Note your power controller, and an incompatible battery may:

  • Do not charge at full power (for example, instead of 33W will go 10W).
  • Cause errors in the operation of the phone (sudden reboots, shutdowns).
  • Swell due to inappropriate charging current.

The exception is some models from the same line (for example, Redmi Note 9 And Note 9 Pro), but even in this case it is better to use the original battery.

How to recycle an old battery?

Lithium-ion batteries should not be thrown into regular trash! They contain toxic substances and may ignite. Proper disposal methods:

  • 🔄 Take it to an electronics collection point (for example, in stores Svyaznoy, M.Video or Eldorado there are special containers).
  • 📦 Give it to the service center - many workshops accept old batteries for free.
  • ♻️ Use recycling programs (For example, Xiaomi periodically holds promotions to accept old batteries).

Before disposal drain the battery to 0% and cover the contacts with electrical tape to avoid short circuits.