Replacement of the battery on Xiaomi Redmi Note 4: a detailed guide with photos and nuances

Xiaomi Redmi Note 4 (codenamed mido) remains one of the most popular budget smartphones even 7 years after release. But time does not spare lithium-ion batteries: after 2-3 years of active use, the battery capacity drops by 30-50%, and the phone discharges in a few hours. If your Redmi Note 4 suddenly turns off at 20-30% charge, the case is swollen or the charge lasts less than a day, it’s time to change the battery.

In this article, you will find a step-by-step battery replacement with a photo, tips for choosing a quality battery, a list of tools you need and answers to frequent questions. We will also reveal a key nuance with calibrating the power controller after replacement, which is often not mentioned in other guides. You can cope with the task yourself - the main thing is to follow the algorithm and take your time.

Signs that it is time to change the battery

Low autonomy doesn't always mean battery wear, sometimes it's software or a faulty charger, but there are clear signs that you need to replace it.

• 🔋 The phone turns off at 15-30% charge, although it used to work to 0%
• 📉 The battery is discharged in 2-3 hours in standby mode (with Wi-Fi and mobile data turned off)
• 🔥 The case of the smartphone swelled or there were gaps between the screen and the back cover
• ⚡ Charging is jerky or interrupted (especially if the cable and power supply are serviceable)
• 📊 Applications like AccuBattery show a capacity of less than 60% of the factory (1800-2000 mAh out of 4100 mAh)

If you have at least 2-3 items on your Redmi Note 4, a battery replacement is inevitable, and you don’t have to delay repairs, because a bloated battery can damage the motherboard or display, leading to more expensive repairs.

⚠️ Attention: If the case of the smartphone is swollen, do not try to open it yourself - the risk of short circuit.

What battery should I use for the Redmi Note 4 (mido)?

The factory battery in the Redmi Note 4 has a capacity of 4100 mAh and a brand BM47 (manufactured by ATL or Sunwoda), and when replacing it, it is important to choose a quality analogue so as not to encounter a fake or low-capacity battery.

Where to buy it?

• 🛒 Official stores: mi.com, AliExpress (sellers with a rating of 98%+) — price between 800 and 1500 ₽
• 🏬 Local service centers – ask for the original battery (sometimes stock remains)
• 🔧 Radio parts stores: "Chip and Deep", "Amperka" - if you need it urgently

The battery models for the Redmi Note 4 are:

• Original Xiaomi BM47 (MBP04HY)
• Premium analogue - ZOP Power (capacity 4200 mAh, 3-pin)
• Budget option - Baseus (capacity 4000 mAh, warranty 6 months)

⚠️ Note: AliExpress batteries often come in low to 0%. Charge them up to 30-50% with a universal charger (e.g. iMax) before installation B6).

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Before buying, check the battery reviews – often fakes give themselves a low capacity (real 2500 mAh instead of the declared 4100 mAh).

Required tools for replacement

To disassemble the Redmi Note 4 and replace the battery, you will need:

Screen suction cup (∅ 5-7 cm)

Plastic mediators or guitar plectra (2-3 pieces)

Cross screwdriver PH00 or PH000

Tweezers with curved ends

Thermoclei or bilateral scotch (to fix a new battery)

Isopropyl alcohol (90%+) and cotton swabs

Fryer (for softening glue)

Multimeter (optional, to check the voltage)

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Where can I get the tools?

• 🔧 Smartphone repair kit – sold on AliExpress or in electronics stores (price 300-600) ₽). Includes screwdrivers, sucker and mediators.
• 🧴 Isopropyl alcohol - in pharmacies (ask "medical alcohol for disinfection") or in radio stores.
• 🔥 Hair dryer - suitable for ordinary household, but better building with temperature adjustment (maximum 60-70)°C).

If you don't have a multimeter, you can check the battery with the AccuBattery app (before and after replacement) to show the actual capacity and condition of the battery.

Step-by-step instructions for replacing the battery

Before starting work, turn off the phone completely and remove it. SIM-Work on a clean surface (better cover the table with paper or cloth).

Step 1: Removing the back cover

The Redmi Note 4's back panel is glued around the perimeter to remove it.

1. Heat the edge of the body with a hair dryer (10-15 seconds each) - this will soften the glue.
2. Install a suction cup at the bottom of the phone (above the microUSB connector).
3. Pull the sucker up with effort, while putting the lid on with a plastic mediator.
4. Carefully swipe the mediator around the perimeter, separating the lid from the body.

If the lid doesn't lend itself, heat it up again. Don't use metal tools, they'll scratch the lid!

Step 2: Disconnect the battery plume

After removing the cover, you will see:

• Battery (takes up most of the space)
• Battery plume (black connector with 3 contacts)
• Camera module and antenna wires (don't touch them unnecessarily!)

To turn off the battery:

1. Unscrew 4 screws with a cross screwdriver (they fix the metal plate above the plume).
2. Carefully tuck the battery connector with a plastic spatula and disconnect it.

⚠️ Warning: If the phone turns on after the plume is disconnected, the battery hasn't been completely discharged. It's dangerous.

Step 3: Remove the old battery

The battery is glued to the body to remove it.

1. Put the battery in a plastic mediator from any angle.
2. Carefully pull the tongue (if any) or put a thin plastic card under the battery.
3. If the glue is too strong, drop the isopropyl alcohol under the battery - it will dissolve the adhesive.

Do not bend the battery or pierce it – it can lead to fire!

Step 4: Installation of a new battery

Before installing the new battery:

• Check the voltage with a multimeter (should be 3.7-4.2V).
• Clear the contacts with alcohol.
• Remove the protective film from the new battery (if any).

Put the battery in place and fix it:

• If the kit is adhesive tape - glue it.
• If not, use double-sided tape or heat-glue (dot!).

Step 5: Assembly of the phone

Collect the phone in reverse order:

1. Connect the battery plume.
2. Twirl the metal plate screws.
3. Install the back cover, having previously cleaned the old glue with alcohol.
4. Press the lid around the perimeter for reliable fixation.

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Don't turn the phone on immediately after assembly! First, charge it for 10-15 minutes to wake up the new battery.

Calibration of the battery after replacement

90% of the problems with the new battery are due to an undischarged power controller. After the battery is replaced, the phone may show an incorrect percentage of charge or quickly discharge.

1. Discharge the phone before automatically shutting down.
2. Charge it to 100% without interruptions (use the original power supply).
3. Turn off the charger and let the phone work for 1-2 hours.
4. Repeat the discharge / charge cycle 2-3 times.

You can also reset calibration data via the engineering menu:

1. Enter the dialer code: ##4636##.
2. Select Battery Information.
3. Click Reset Battery Statistics (if there is one).

If after calibration the phone still discharges quickly, check:

• 🔌 Cable and power supply (possibly they do not give the right current).
• 📱 Background applications (use Settings) → Battery → Battery utilization).
• 🔄 Firmware (on custom) ROM LineageOS can be confused by charge accounting).

Frequent errors when replacing the battery

Even experienced users sometimes make mistakes that cause their phones to break down, and here are the most common ones:

• 🔧 Using metal tools – scratches the body and can close contacts.
• 🔥 Overheating with a hair dryer - if you blow hot air (>80°C. You may damage the screen or board.
• 🔋 Installing a battery with a different polarity will result in a short circuit.
• 🧴 Ignoring contact cleaning – oxides impair contact and lead to poor charging.
• 📱 Turning on the phone immediately after assembly - the new battery should "rest" for 10-15 minutes.

If the battery swells after 1-2 months, you probably bought a fake battery. Xiaomi's original batteries last 2-3 years when used properly.

How much does it cost to replace the battery in the service?

If you're not sure about your abilities, you can contact the service center.The cost of replacing the battery with a Redmi Note 4 in 2026:

In the official service, you will be given a warranty of 6-12 months, but you will have to wait longer. Private craftsmen work faster, but the risk of running into an unscrupulous performer is higher.

If you decide to change the battery yourself, the total cost will be 500-1500. ₽ (battery) + 300–600 ₽ (It's 2-3 times cheaper than the service.

FAQ: Answers to Frequent Questions