Replacement of the battery on Xiaomi Redmi 8: a complete guide with photos and nuances

Why the Redmi 8 battery fails and when to change it

The Xiaomi Redmi 8, launched in 2019, features a 5,000 mAh non-removable battery, one of the model’s key advantages. However, even the most reliable batteries degrade over time. On average, after 2-3 years of active use, capacity drops by 30-40%, and by 4-5 years, many users experience sudden shutdowns with 20-30% charge or a complete refusal to charge.

Typical signs of a “dying” battery on the Redmi 8:

• 🔋 The phone discharges in 3-4 hours with moderate use (previously held a day).
• 🔌 Charging jumps: it is 100%, then drops sharply to 1%.
• ⚡ The device warms up during charging or spontaneously shuts down.
• 📉 Settings menu → The battery state shows a capacity below 70%.

The manufacturer claims a battery life of 500 full charge cycles, but the real life depends on the operating conditions. For example, constant charging "up to 100%" and discharging "to zero" reduce the battery life by 2 times. If you notice at least 2-3 symptoms from the list, it's time to think about replacing. In the service center, the procedure will cost 1,500–3,000 ₽, But with the tools and patience, you can save money by doing everything yourself.

What tools and spare parts will be needed

To replace the battery on Xiaomi Redmi 8 will require a minimum set of tools, most of which can be found in the remakes for smartphones (cost) ~500–800 ₽). Here's the full list:

The battery is a mixed story. Xiaomi's original batteries cost 1,200-1,800. ₽, But there are many counterfeits on the market, and the alternative is quality Patona or Remax (800-1,200). ₽). The main thing is to check:

• 🔍 Presence of hologram and serial number on the package.
• 📦 Capacity of at least 5000 mAh (indicated on the battery sticker).
• ⚡ Compatibility with the model M1908C3JG (code code for Redmi 8).

⚠️ Note: Don’t buy batteries with AliExpress for less than 600 ₽ — This is a guaranteed Chinese with a capacity 2-3 times smaller than the declared one.

Preparing the phone for disassembly: security steps

Before you start disassembling, you need to turn off the device and take precautions. First, turn off the Redmi 8 in the standard way (press the power button and select Turn off). If the phone does not respond, force it to discharge, leaving it on for 12-24 hours.

Next:

Extract. SIM-card and memory card (tray on the right)

Remove the cover and protective film (if any)

Wash the body with alcohol to remove fat and dirt

Make a backup of the data (in case of error)

Prepare the workplace: flat surface, good lighting-->

Pay special attention to the glue under the back cover. On the Redmi 8, it is strong enough that you can not do without heating. Use a dryer at minimum power (temperature ~60-70 ° C) and warm the edges of the body around the perimeter for 2-3 minutes. Don't overheat! Plastic can deform, and the display - peel off.

⚠️ Warning: If you use a thermal air station, keep the nozzle 5-7 cm away from your phone. Direct hot air flow can damage the camera or display plumes.

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Before heating, place the phone on a soft cloth (such as a microfiber) to avoid scratching the glass or body.

Step-by-step: how to disassemble Xiaomi Redmi 8

The Redmi 8 is more difficult to disassemble than Xiaomi’s flagship models due to its dense layout and a lot of glue.

Step 1 Remove the back cover

After you warm up with a hairdryer, insert a plastic mediator into the gap between the lid and the body (start at the lower right corner where the SIM card is located). Carefully drive the mediator along the edge, separating the glue. If the lid does not respond, warm up for another 1-2 minutes. Don't force - you can break the latches!

Step 2: Spinning the screws

Under the lid, you'll see 12 screws of varying lengths (pictured below), use a PH00 screwdriver and unscrew them in a separate box to avoid losing them. Note: the screws on the antenna modules are shorter than the others.

Step 3: Disconnect the plumes

Now you need to turn off the plumes going to the motherboard:

1. Carefully tuck the battery connector (black, at the bottom of the board) with a plastic spatula.
2. Disconnect the display plume (wide, at the top).
3. Remove the camera plume (small, to the right of the battery).

Step 4: Remove the old battery

The battery is glued to the body with double-sided tape. Tuck it in from any angle and slowly pull it up. If the tape doesn't lend itself, drop some isopropyl alcohol (90%+) under the edge of the battery, it will dissolve the glue. Don't use metal objects to keep the battery from piercing!

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The most dangerous part is to disconnect the battery plume, and if you do it wrong, you can close the contacts and burn the motherboard.

Installation of a new battery and assembly of the phone

Before installing a new battery, check it for defects, such as bloating, scratching, or contact damage.

1. Battery stowage

Place the battery in the socket so that the connector matches the contacts on the board. Easy press the battery - it should lie flat, without distortion. If the new battery is thinner than the old one, use double-sided scotch (comes with) to lock.

2. Connecting plumes

Put all the sleeves back in the same order:

• 📸 First the camera (small connector on the right).
• 📺 Then the display (wide plume at the top).
• ⚡ Last of all, the battery (black connector at the bottom).

Make sure all connectors are snapped before the characteristic click.

3. Rotary screw twisting

Put all 12 screws in their seats, keeping them in length. You don't have to pull them, you don't have to pull them, you just have to do it, and if you don't screw them, make sure that you've got any dust or debris in it.

4. Posting of the back cover

Apply a new layer of glue (such as the B-7000) around the perimeter of the case or use the original two-way tape from the battery kit. Press the lid and leave the phone under load (such as a book) for 10-15 minutes.

⚠️ Warning: If the phone doesn't turn on after assembly, check: Is the display plume connected correctly (frequently a skewed connector) is the battery contacts closed (check the charge for foreign objects) is the new battery charged (sometimes they come in empty). Calibration of the battery after replacement The new battery requires calibration so that the charge controller correctly determines its capacity. By skipping this step, you risk inaccurate data on the level of charge or accelerated battery degradation. Calibration instruction: Full discharge. Use your phone before you turn off automatically (do not charge even if you have a low charge warning). Charge to 100%. Connect the original RAM and wait for full charge. Don't interrupt the process! Additional 2 hours on charge. Once you reach 100%, leave your phone on for another 120 minutes, which will reset the controller's memory. Recycle. Recharge the phone to 0% again and charge to 100%. Now calibrate complete. After calibration, check the actual battery capacity in the engineering menu: Enter the code ##4636## in the Phone app. Select Battery Information. Compare Charge Level (should be 100%) and Battery Health (optimum 95-100%). 💡If after calibration the phone discharges quickly, check the background processes in Settings → Battery → Battery use. Auto-update messaging or social media are often to blame. Frequent errors and how to avoid them Even experienced users make mistakes when replacing the battery. Here are the most common of them and ways to prevent them: Error Consequences How to avoid Using metal tools to tamper with the battery Puncture battery, risk of fire Use only plastic mediators Overheating the body with a hairdryer Deformation of plastic, detachment of the display Keep the hairdryer at a distance of 10 cm, temperature not higher than 70 ° C Wrong connection of the battery plume Short circuit, failure of the motherboard Disconnect the plume first, connect the latter Use of the non-original battery without checking Bloating, rapid discharge, damage to the controller, the battery charge is not responsible for 90% of the phone. Make sure the screws are not pulled over (this can close the contacts).If the battery runs out after a few hours after replacing, background processes or a poor battery are likely to cause. Install the AccuBattery app (available on Google Play) for diagnostics. FAQ: Theoretically, yes, but in practice, it's almost impossible. The glue on Redmi 8 is very strong, and without softening, there's a high risk of breaking the lid latches. If there is no hair dryer, try putting the phone on the heating battery for 10-15 minutes (temperature should not exceed 50).°How much does it cost to replace a battery in a service center? Prices vary by region and status of service: Official Xiaomi service: 2,500-3,500 ₽ (Informal workshops: 1,200–2,000 ₽ (often-pattern). Self-sustained replacement: 600–1,500 ₽ (battery + Note that informal services may use cheap AliExpress batteries that will last only a few months. How do I check if I sold the original battery? The original Xiaomi Redmi 8 battery has the following features: Hologram sticker with serial number, 5,000 mAh capacity (labeled) Model code: BM4D or BM4E. Weight. ~100 grams (fakes are often easier) You can also check the battery using the app. AIDA64 (If the capacity is very different from the declared one, it is a fake. What if the phone overheats after the battery is replaced? Overheating after the battery is replaced can be caused by: Incorrect installation (the skewed battery puts pressure on the board). Close contacts (check if the battery has any debris). The solution: take apart the phone, inspect the battery and board, replace the battery with another if necessary. Can you use the Redmi 8A battery in the Redmi 8? No, despite the appearance, the batteries of these models are incompatible. The Redmi 8A battery has a different connector and shape (the BM4C model code). Installing a non-native battery can lead to: Incorrect operation of the charge controller. Battery bloatom. Damage of the motherboard.