Replacement of the battery on Xiaomi Redmi Note 6 Pro: detailed instructions with nuances

The life of lithium-polymer batteries in smartphones rarely exceeds 2-3 years of active use. Xiaomi Redmi Note 6 Pro, released in 2018, today often faces problems: fast discharge, sudden shutdowns at 20-30% charge or battery bloating. If your device began to “glutch” this way, most likely, it’s time to replace the battery. In the service center for this procedure will ask from 1500 to 3000 rubles, but with tools and patience you can cope on your own in 40-60 minutes.

In this article, we'll take a step-by-step look at the specifics of the Redmi Note 6 Pro, from choosing a compatible battery to calibrating after installation. We'll focus on the critical points that are often overlooked in general instructions: how not to damage the plumes, how the original batteries differ from their counterparts, and why the percentage of charge can be "discharged" after replacing. If you've never disassembled a smartphone, don't worry: the design of this model is relatively beginner-friendly.

⚠️ Warning: A bloated battery is a risk of fire if puncture occurs. If the phone case is deformed, don't try to remove the battery yourself. Contact the service or use protective gloves and glasses while working outdoors.

1.How to know if the battery is time to change: 5 clear signs

Not all power problems are battery related, for example, rapid discharge can be caused by background processes or a worn-out charger, but there are symptoms that clearly indicate a battery failure:

• 🔋 The phone turns off at 20-40% charge and only turns on after being connected to the network, which is a sign of heavy cell wear, the controller miscalculates the residual capacity.
• 📱 The phone's body is open: there's a gap between the back and the screen, or the smartphone is walking on a flat surface, and this is how the battery bloats.
• ⚡ Charging is interrupted or jerked, although the cable and power supply are in good condition, and the culprit may be oxidation of the battery contacts or damage to the thermistor.
• 🔥 The phone heats up a lot in the battery area even when it's under minimal load. It's dangerous -- short circuit risk!
• 📉 In the Settings menu → Battery state is less than 70% of the original capacity of the Redmi Note 6 Pro – 4000 mAh.

If you see at least 2-3 signs from the list, the battery needs to be changed. For accurate diagnosis, you can use applications like AccuBattery (reveals real wear) or AIDA64 (tests of voltage under load).

2. Battery selection: original vs analogues, what to look at

The original battery for the Redmi Note 6 Pro has an MBJ405740 and a capacity of 4000 mAh (rated voltage 3.85V).However, after 2020, Xiaomi stopped supplying them retail, so the market is dominated by analogues.

Among the analogues, well-established batteries from Patona, Baseus and Remax - they often come with already glued double-sided tape and heat pad. Avoid "nouneim" manufacturers: such batteries can have an understated capacity or a poor controller, which will lead to overheating or rapid wear.

⚠️ Warning: Batteries with a capacity of >4,000 mAh (e.g., 4500 mAh or 5000 mAh) are a hoax! The Redmi Note 6 Pro controller does not support larger batteries, and real tests show that such “improved” counterparts rarely exceed 3,500 mAh.

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Before buying, check the seller's reviews on the marketplace. Often fakes are disguised as "originals" with Mi stickers on the package. Ask the seller for a photo of the real product with a scale or next to a coin for scale.

3. Replacement tools: what will be needed

The Redmi Note 6 Pro doesn’t need expensive tools to disassemble, but some trivia is essential.

• 🔧 Plastic mediators (2-3) to separate the back cover. Metal blades can scratch the body.
• 🔨 Cross screwdriver (size PH00 or PH0) - for the middle board fastening screws.
• 🧲 Magnetic mat or container - so as not to lose small screws (there are about 15 pieces!).
• 🔥 Hair dryer or thermo-air station - for softening the glue (temperature) 60-80°C).
• 🧴 Isopropyl alcohol (90%+) — cleaning up glue residues and contacts.
• 📦 New double-sided tape (e.g., 3M 9448A) if not included with the battery.
• 🛡️ Gloves and glasses when working with a bloated battery.

Also useful is a plastic card (for example, a bank card) - it is convenient to snip the battery after heating. If you plan to repair equipment often, consider buying a set for disassembling smartphones (costs ~ 500-1000 rubles on AliExpress).

Step-by-step: how to disassemble the phone and replace the battery

Before you start, turn off your phone completely, and remove the SIM- memory card. Work on a clean, well-lit surface. If the battery is blown up, don't push it out so you don't break through the shell.

Turn off the phone and remove the tray SIM-kart|

Remove the case (if any) and clean the case of dust |

Prepare tools and a new battery |

Wear gloves (if the battery is swollen)|

Take a picture of the location of the screws before disassembly

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Step 1 Remove the back cover

Heat the edge of the back cover with a hair dryer (30 seconds on each side) at 60-70°C. Insert a plastic mediator into the gap between the cover and the case at the USB-Type C connector and gently lead along the perimeter. The cover is held on the latches - do not apply force so as not to break the clips.

⚠️ Warning: Under the lid is a fingerprint scanner plume (if your model has one). Don't pull the lid sharply - first unplug the plume!

Step 2. Shutting down the battery

When you remove the lid, you'll see the battery covered with black film. At the top of the board, find a battery connector (usually red or orange), gently tuck it in with a plastic spatula to turn off the power. Don't use metal tools, you can close the contacts!

Step 3: Remove the old battery

The battery is glued to the body to remove it.

1. Plug on the battery strips of tape (you can use stationery) and pull them, while putting on a plastic card.
2. If the battery fails, heat it with a hair dryer (70-80°C) for 1-2 minutes.
3. Remove the remains of the glue from the body with isopropyl alcohol.

Step 4: Installation of a new battery

Before installation, make sure that the new battery contacts are free of protective film. Stick bilateral tape (unless it is applied beforehand) and gently put the battery back in place. Connect the power connector and make sure that the plumes do not overflex.

Step 5: Build the phone

Make sure all screws are swirled into their seats (their length may vary!). Connect the fingerprint scanner plume (if disconnected) and snap the back cover starting at the bottom. Don't push the center of the cover - this can damage the display.

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After assembly, don't turn the phone on right away! let the glue under the battery "grab" for 10-15 minutes to avoid the battery shifting when vibrating.

5. Calibration of the new battery: why it matters

After the battery is replaced, the Redmi Note 6 Pro power controller may misrepresent the percentage of charge, such as showing 100%, and after 10 minutes, sharply “sink” to 70%. This is because the system does not “know” the real characteristics of the new battery.

1. Full discharge: use the phone before it automatically shuts down. Don't turn it on right away!
2. Charging to 100%: connect the original RAM and wait for full charge (the indicator should show 100%).
3. Additional “recharging”: after reaching 100%, leave your phone on charging for another 1-2 hours.
4. Battery reset: Go to the engineering menu by dialing ##4636##, select Battery information and click Battery calibration (if available).

Repeat the discharge-charging cycle 2-3 times, after which the percentage of charge will be displayed more accurately. If the problem persists, try resetting the cache via recovery (Volume Up + Power when the phone is off).

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To speed up calibration, you can use the Battery Calibration app from Google Play, which resets the batterystats.bin file, which stores data on the wear and tear of the old battery.

6. Frequent mistakes and how to avoid them

Even experienced tycoons sometimes make mistakes when replacing a battery, and here are the most common mistakes and ways to prevent them:

• 🔌 Battery plume damage: never pull the wires! Only take the plastic connector.
• 🔥 Overheating with a soldering iron: If you solder a thermistor (in rare cases), use a temperature not higher than 300°C and a flux without acid.
• 📱 Improper build: screws of different lengths! In the Redmi Note 6 Pro, the screws under the motherboard are shorter than the lid screws.
• 🔋 Ignoring calibration: Without it, a new battery can sink from 50% to 1% in a matter of minutes.
• 🧲 Lost screws: Use a magnetic mat or scotch to fix the parts as you extract.

If the phone is not switched on after replacement:

1. Check if the battery connector is connected.
2. Make sure your contacts are not contaminated (wipe with alcohol).
3. Connect the charger – sometimes the controller needs to “push” the voltage.
4. If nothing helps, the motherboard may be damaged (e.g., from static electricity).

7. How long will the new battery last: how to extend the service life

The average life of a lithium polymer battery is 500-800 charge cycles. To make the new battery on the Redmi Note 6 Pro last longer, follow these rules:

• 🔋 Avoid deep discharge (below 10%) and recharge (above 90%). Optimal range is 20-80%.
• ⚡ Use original or certified RAM (e.g. Xiaomi 18W). Cheap charging can damage the controller.
• 🌡️ Do not operate the phone in temperatures below 0°C or above 40°C. For example, do not leave it in the sun in the car.
• 📵 Disable background processes (developer settings → Do not remain active) and auto-update applications using Wi-Fi/mobile.
• 🔄 Once every 3 months, perform a full discharge-charging cycle to calibrate the controller.

If you notice that the new battery is rapidly discharged, check the charge consumption of the applications in the settings (Settings → Battery → Charge Use). Often the fault of messengers (for example, Telegram in the background) or games with high energy consumption.

8. Alternative options: when self-activity is dangerous

It is not always justified to replace the battery on your own.

• 💥 The battery swelled so much that it warped the screen — a risk of damaging the display when disassembled.
• 🔧 You haven’t disassembled smartphones before and are afraid of damaging plumes or the motherboard.
• 📱 The phone does not turn on after a failed replacement - it may be cut contacts or the power controller has failed.
• 🛠️ Thermistor soldering is required (rarely encountered but requires experience with a soldering station).

The cost of replacement in the service for the Redmi Note 6 Pro in 2026:

If you decide to use the service, choose workshops with a guarantee for work (at least 1 month), ask to show a new battery before installation - so you will make sure that you do not get a used part.

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Xiaomi service centers often refuse to repair models older than 3 years (like the Redmi Note 6 Pro).

FAQ: Answers to Frequent Questions