Replacement of the battery on Xiaomi Redmi 4 Pro: disassembly, battery selection and step-by-step repair

Xiaomi Redmi 4 Pro is one of the most popular budget smartphones of 2017, but even after 5-7 years of operation, the battery loses up to 60% of its capacity. If your device discharges in a couple of hours, turns off at 30% charge or overheats during charging, it’s time to think about replacing the battery. In this article, we will discuss how to do it yourself without contacting the service center.

The procedure does not require a soldering iron or special skills, but it will require care: damage to the display plume or rupture of flexible contacts can turn into expensive repairs. We will describe in detail each step, from choosing a new battery to assembling the case, and give tips on how to extend the life of a new battery.

Let's go!

Signs of battery wear: when is it time to change?

Lithium-polymer batteries in smartphones degrade even when properly operated. In the Redmi 4 Pro with a factory battery capacity of 4100 mAh after 3-4 years, the real capacity often drops to 2000-2500 mAh. Here are the key symptoms that the battery needs to be replaced:

• 🔋 The smartphone is running out of power. 2-3 hours with moderate use (social networks, messengers).
• 🔥 The body is noticeably heated in the battery area (especially when charging).
• 📉 The percentage of charge “jumps”: for example, from 40% immediately drops to 15%.
• ⚡ The charge is interrupted or is jerking (fast, then slow).
• 🛑 The device is switched off when 20-30% charge and not activated without connecting to the network.

If you have at least 2-3 items on your Redmi 4 Pro list, the battery is clearly worn out.

1. Type on the keyboard ##4636##.
2. Select the Battery Information item.
3. Compare the current capacity to the factory capacity (4100 mAh), and if the difference is greater than 30%, it's time to act.

⚠️ Attention! Don't confuse battery wear with software problems. If the smartphone is quickly discharged due to background application activity (checked in Settings) → Battery, first try resetting to factory settings or reflashing the device.

What battery to choose for Redmi 4 Pro: original vs analogues

Factory battery for Redmi 4 Pro is marked BM47 (or BM48 for some batches) and a capacity of 4100 mAh. However, the original batteries from Xiaomi are now almost not available in the free market - they were replaced by analogues from third-party manufacturers.

For most users, the best choice is premium analogues (for example, ZOP They're just on the power. 5-10% They are inferior to the original in capacity, but stand in 2 Avoid batteries without labeling or at suspiciously low prices (less than that). 800 ₽) — They are often made of low-quality cells prone to bloating.

When buying, pay attention to:

• 🔍 Availability of a protective controller (must be included or soldered into the battery).
• 📏 Battery thickness: original - 3.85 mm, analogues can be thicker (up to 4.2 mm), which will complicate the assembly.
• 🔋 Connector Type: The Redmi 4 Pro has this 3-pin scattering (not to be confused with the 2-pin Other Xiaomi models).

⚠️ Attention, increased capacity batteries (5000+ mAh) require modification of the body - they are thicker than the original on 1-2 Without further work, the lid will not close, and the pressure on the battery may cause damage.

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Check the reviews of the seller on the marketplace before you buy. Often, under the guise of “original” batteries, fakes are sold with a capacity 2 times lower than the declared one. Use a tester (multimeter) to check the real capacity after you buy.

Replacement tools: what you will need

To disassemble the Redmi 4 Pro and replace the battery, you will need a minimum set of tools, most of which can be purchased from electronics stores or ordered from AliExpress in a smartphone repair kit.

• 🔧 Plastic shoulder blades (mediators) — 2-3 (for the purpose of sliding and sliding).
• 🔨 The screwdriver. PH00 (hull-rotor).
• 🧲 Magnetic mat or tray (so as not to lose screws).
• 🔥 Dryer or thermo-air station (to soften the adhesive under the battery).
• 🧴 Isopropyl alcohol (90%+) — clean-up.
• 📦 New double-sided tape (for battery fixation).
• 🔋 Battery tester (optional, to check capacity).

If you don't have a hair dryer, you can use a regular household one, but you need to warm carefully so as not to melt the plastic of the case. The alternative is a special glue solvent (for example, the B-7000), but it acts slower and can leave traces.

Important: Don’t use metal screwdrivers to slap the lid, it will lead to scratches or chips, and plastic blades can be replaced with guitar mediators or bank cards (but they are less convenient).

Buy a new battery with a suitable connector|Prepare the workplace (clean table, good lighting)|Backup of data (in case of damage)|Charge your smartphone to 30-50% (safe)|Disconnect the smartphone and remove SIM-map-->

Step-by-step: how to disassemble the Redmi 4 Pro and replace the battery

Now, to the most critical part of disassembling the device, follow the instructions carefully to avoid damaging the plumes or the board. In the Redmi 4 Pro, the battery is glued to the body, so you have to carefully separate it with heat.

Step 1: Turn off and prepare the smartphone

1. Turn off the Redmi 4 Pro with a long press of the power button.
2. Remove the tray for SIM-cards (use a paper clip or special key).
3. Place the device on a flat surface with the screen down.

Step 2. Remove the back cover

1. Heat the lid edge with a hair dryer (60-70°C) for 1-2 minutes. This will soften the glue.
2. Insert a plastic blade into the gap between the lid and the body (start at the bottom corner where the charging connector is).
3. Carefully drive the shoulder blade around the perimeter, separating the lid. Be careful at the volume and power buttons - there are plumes!

Step 3: Disconnect the battery plume

1. After removing the lid, you will see a battery with a black plume glued to the motherboard.
2. With a screwdriver, unscrew one screw that fixes the metal plate over the battery connector.
3. Put a plastic scapula on the connector and gently unplug the plume.

Step 4: Remove the old battery

1. Heat the battery with a dryer (no higher than 80°C!) for 3-5 minutes to soften the glue.
2. Pick up the battery with a plastic spatula from any corner and slowly pull up. If it resists, warm up again.
3. After extraction, clean the seat from the glue residues with isopropyl alcohol.

Step 5: Installation of a new battery

1. Remove the protective film from the contacts of the new battery.
2. Stick bilateral tape to the back of the battery (or use B-7000 glue).
3. Set the battery in place, connect the plume to the connector and fix the metal plate with a screw.

Step 6: hull assembly

1. Make sure all the plumes are connected (display, buttons, speaker).
2. Close the back cover, starting at the top (where the camera is) and press it until you click.
3. Turn on your smartphone and check the battery power in Settings → Battery status.

Frequent Mistakes and How to Avoid Them

Even with careful disassembly, you can make mistakes that will cause your smartphone to fail, and here are the most common problems and ways to prevent them:

• 🔌 Display plume damage occurs when the lid is not removed neatly. Solution: use only plastic blades and do not put too much effort into it.
• 🔥 Overheating the battery when heated can cause bloating or even fire. Solution: heat for no longer than 5 minutes and don't point the hair dryer to one point.
• 📉 Incorrect charge display (e.g. 0% when connected to charge) Solution: reset battery calibration data via the engineering menu (#4636## → Battery information → Reset).
• 🔋 Quick discharge of the new battery. Solution: execute. 2-3 full charge/discharge cycle for “swinging” the battery.

If your smartphone gets overheated or discharges quickly after you've replaced it, you may have installed a poor battery, check its capacity using the AccuBattery app (available on Google Play), and if the actual capacity is much lower than the declared capacity, return the battery to the seller.

⚠️ Attention! If you notice that the old battery is swelling (the cover of the case is raised), do not try to puncture or bend it! Lithium polymer batteries can ignite if damaged. Dispose of such a battery at special reception points.

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The most common reason for a new battery failure is the wrong calibration. After replacement, be sure to complete 2-3 full charge cycles (0% to 100%) for the controller to work properly.

Calibration of the battery after replacement

The new battery may not work properly if the Redmi 4 Pro's power controller doesn't "know" the parameters, and you need to calibrate it, a procedure that synchronizes the capacity data between the battery and the system.

1. Discharge the smartphone before automatically switching off (0%).
2. Connect to charging and wait 100% (do not turn on the device while charging!).
3. Turn off the charging, turn on the smartphone and again wait for the discharge to 0%.
4. Repeat the cycle 2-3 times – this will help the controller to accurately determine the capacity.

To speed up the process, you can use the AccuBattery application:

1. Install it from Google Play.

2 Go to Battery Health section.

3. Press Calibrate and follow the instructions.

After calibration, check the actual battery capacity in the engineering menu (#4636##). If it matches the declared capacity (for example, 4000 mAh for analogue), it is done correctly.

How to prolong the life of a new battery

Even a high-quality battery will not last long if you do not follow the rules of operation.

• 🔌 Avoid full discharge. Optimal charge range — 20-80%. Regular discharges to 0% shorten service.
• ☀️ Don't leave your smartphone in the sun or in the car. overheating above 40°C accelerates the degradation of lithium polymer cells.
• 🔋 Use original or certified RAM. Cheap charging with unstable voltage spoils the battery.
• 📵 Disable background apps that consume charge (e.g. Facebook, constant sync messengers).
• 🌙 Charge your smartphone overnight? Better not — keep it connected no longer. 2-3 hours after 100%.

It’s also helpful to turn off fast charging (if enabled via Settings → Additional → Quick Charging).Although Redmi 4 Pro doesn’t support Quick Charge, some firmware emulates accelerated charging, which increases battery heat.

The average battery life when properly operated is 3-4 years. If you notice that after 2 years the capacity has started to fall again, repeat the replacement procedure (now you know how to do it!).

FAQ: Answers to Frequent Questions