Replacement of the battery on Xiaomi Redmi 9: full instructions with photos and videos

Xiaomi Redmi 9 is one of the most popular budget smartphones, but over time, even its reliable battery capacity of 5020 mAh begins to lose capacity. If the phone runs out in a few hours, suddenly turns off at 20-30% charge or the case is swollen, it’s time to think about replacing the battery. In this article, we will discuss how to change the battery on Redmi 9 (models M2003J15SS, M2004J19C and the like), without contacting the service center.

The replacement process does not require professional skills, but requires accuracy, patience and the right tools. We will tell you which battery to choose (original or analog), how to safely disassemble the phone, disconnect the old battery and install a new one with step-by-step photos and videos.

Signs that the Redmi 9 battery needs to be replaced

It's not always a fast discharge of the phone that's related to battery wear, and sometimes it's software failures or apps' background power consumption, but there are some obvious symptoms that indicate that the battery is wearing out physically:

• 🔋 Phone's running out of power. 3-4 hour with moderate use (previously held charge) 1-2 day-day).
• ⚡ The percentage of charge “jumps” (for example, from 40% immediately drops to 15% after rebooting).
• 💥 The phone body swelled (notably over the gap between the screen and the frame or the "slamming" display when pressed).
• 🔌 Charging is slow or interrupted (especially if the cable and power supply are in good condition).
• 🌡️ The phone gets very hot during charging or playing.

If you're watching at least 2-3 The probability of battery wear is the 90%. Check the status of the battery can be using applications like AccuBattery (shows real capacity) or through the engineering menu (##4636## → Battery information. If the actual capacity fell below 3500-4000 Mach, it's time to change the battery.

⚠️ Attention: Bloated battery is dangerous! It can burst or ignite when mechanically exposed. If the phone case is deformed, don't try to disassemble it yourself - contact the service.

What battery to choose for Xiaomi Redmi 9: original vs analogues

There are three types of batteries available for Redmi 9:

1. Original (from Xiaomi) – the most reliable, but expensive (1500-2500) ₽). Supplied in branded packaging with a hologram, have factory markings BM4X or BM4Y.
2. Licensed analogues (e.g. from ZMI, Baseus, Remax – cheaper (800–1500) ₽), Often they are not inferior in quality to the original.
3. No-name analogues (from AliExpress, markets) - the cheapest (300-700) ₽), But the risk of getting married or having a low capacity is high.

We recommend choosing batteries with a real capacity of at least 4800 mAh (indicated on the label).

• 🔍 Marking: Must match the original (MBJ4063, BM4X or BQ-506).
• 📦 Package: the set must have adhesive strips to fix the battery.
• 📅 Production Date: Fresh batteries (not older than 6 months) retain capacity longer.

Where to buy? Look for original batteries on Mi Store, Svyaznoy or M. Video. Analogues on AliExpress (sellers with a rating above 98%) or in trusted online stores (Beru, Ozon). Before buying, check reviews and photos of real customers - often sellers slip batteries of lower capacity.

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Before you buy, ask the seller to send you a photo of the battery with a label, and the original should have a hologram, a clear label, and a production date.

Battery Replacement Tools: What You Need

To replace the battery with the Redmi 9, you will need a minimum set of tools, most of which can be purchased from electronics stores or ordered from AliExpress in a phone repair kit (cost). ~500–1000 ₽).

List of mandatory instruments:

• 🔧 Plastic blades/mediators (2-3 (a) - for the careful liding and disconnection of the plumes.
• 🔨 The screwdriver (PH00 or PH0) — screw-twisting.
• 🧲 Magnetic mat or container – to avoid losing small screws.
• 🔥 Hair dryer or thermo-air station - to soften the glue (if the battery is glued strongly).
• 🧴 Isopropyl alcohol (90%+) — glue-residue.
• 🔋 New battery - with adhesive strips in the kit.
• 📱 Suction (optional) - helps to remove the back cover.

Also prepare the workplace: a clean desk with good lighting, no carpets (so as not to lose details), it is advisable to use an antistatic bracelet or periodically touch an earthed object (for example, a heating battery) to avoid static discharge, which can damage the motherboard.

⚠️ Warning: Do not use metal blades or knives to lid the lid! They can scratch the body or damage the plumes. Plastic mediators are safer.

Buy a new battery with adhesive stripes | Prepare tools (screwdriver, shoulder blades, hair dryer) | Make a backup of data | Charge the phone to 30-50% (for safety) | Clear the workplace of garbage and dust-->

Step-by-step: how to disassemble Xiaomi Redmi 9 and replace the battery

Now, to the most critical stage, disassembling the phone and replacing the battery, follow the instructions in strict order to avoid damaging the plumes or the board.

Step 1 Turn off the phone and remove it. SIM-map.

Press and hold the power button, select Turn off. Pull out the tray for the power button. SIM-paper-card.

Step 2. Heat the back cover with a hair dryer. Redmi 9 has adhesive fixation of the cover. Heat it around the perimeter with a hair dryer at 60-70°C for 2-3 minutes. This will soften the glue and make it easier to remove.

Step 3. Put the lid on with a plastic spatula.

Start at the bottom corner (near the USB-C connector). Carefully insert the mediator into the slot and lead along the case, separating the lid. If you feel resistance, warm up the place again.

Step 4: Unscrew the midframe screws.

Once you remove the lid, you'll see 10 screws (of different lengths!) take a picture of their location or put them in order, which will help you not to get confused when you build them. Use a PH00 screwdriver.

Step 5. Disconnect the battery plume.

Carefully put the black battery plume connector on a plastic blade. Don't pull the wires, just the connector! This will prevent the contacts from breaking.

Step 6. Remove the old battery.

If the battery is glued, put a plastic spatula on it and pull it up slowly, and you can use a thread or a guitar string to cut through the glue. Don't bend the battery!

Step 7. Install a new battery.

Remove the protective film from the adhesive strips on the new battery and press it to the installation site. Connect the plume back (should be clicked).

Step 8: Put the phone back together.

Make sure all plumes are connected, twist the screws, press the back cover (you can warm up with a hairdryer for better fixation).

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The most common mistake when replacing a battery is to connect the plume incorrectly, and if the phone doesn't turn on after assembly, check if the battery connector is sitting tight in the socket.

What to do after battery replacement: calibration and testing

So, you've successfully replaced the battery, and now you need to calibrate it so that the phone correctly displays the percentage of charge.

1. Completely discharge the phone before automatically shutting down.
2. Charge to 100% without interruptions (use the original power supply).
3. Turn off the charger and turn on the phone. If the charge percentage is less than 100%, charge it again to full.
4. Repeat the cycle 2-3 times for accurate calibration.

Also check:

• ⚡ Charging speed: should be ~18 W (using the original RAM).
• 🔋 Running time: the new battery should hold a charge at least 30% longer than the old one.
• 🌡️ Heat: The phone should not warm much when charging or loading.

If the phone is quickly discharged or does not charge after replacement, the following problems may occur:

• 🔌 Bad contact of battery plume - check if it sits tightly in the connector.
• 🔋 Marriage of a new battery – try testing it on another phone.
• 📱 Software failure – make a reset settings (Settings) → The phone. → Resetting settings).

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After you replace your battery, install the AccuBattery app (Android) and keep track of your discharge schedule for a week to help you identify possible problems early on.

Common mistakes when replacing a battery and how to avoid them

Even experienced users sometimes make mistakes that can cause a phone to break.-5 Mistakes and ways to avoid them:

1. Use of metal tools → It scratches the body or damages the plumes. Solution: only use plastic blades.
2. Overheating the lid with a hair dryer → melting plastic or peeling paint. Solution: Keep the hair dryer at a distance of 10 cm and do not heat one place for longer than 10 seconds.
3. Installing a battery without adhesive strips → the battery will hang around and can tear off the plume. Solution: use double-sided tape or buy a battery with stripes in the kit.
4. Tangled screws → short circuit or board damage. Solution: put the screws in order or photograph their location.
5. Ignoring the swelling of an old battery → Solution: if the battery is swelling, don't try to retrieve it yourself, take it to the service.

Another common problem is that the phone doesn't turn on after assembly, and the reasons may be:

• 🔌 Not connected battery plume or display.
• 🔧 Clutched cable (check if the plume is pinched with a lid).
• 📱 The settings are off. BIOS (It is completely discharged and charged).

⚠️ Warning: If after replacing the battery, the phone overheats, discharges quickly or does not charge, immediately turn it off and check the connection of the plumes. Prolonged operation with the battery installed incorrectly can lead to fire!

Video Instructions: Replacing the battery with Xiaomi Redmi 9

For clarity, we recommend you to check out the video manual, and we have selected the best videos in Russian, which show in detail the process of disassembly and replacement:

• 🎥 Replacement of the Redmi 9 battery - Step-by-step (channel "Phone Repair")
• 🎥 How to disassemble Xiaomi Redmi 9 without damage (Gadget Repair channel")
• 🎥 Review of the original and unoriginal battery for the Redmi 9

Notice the following:

• The author puts the cover (usually starting from the bottom corner).
• How to fix the plumes, so that they do not interfere.
• What tools are used to remove the battery?

If you still have questions about any stage, rewrite the time in the video and ask a question in the comments - we will help you figure it out!

FAQ: answers to frequent questions about replacing the Redmi 9 battery