How to change the battery on Xiaomi Redmi Note 4 without losing firmware

Xiaomi Redmi Note 4 (codenamed mido) remains popular even years after its release, thanks to its robust stuffing and upgrade capabilities, but over time, even the best battery loses capacity: the phone runs out in a few hours, shuts down at 20-30% charge or refuses to turn on, and if you encounter these problems, replacing the battery is the only solution.

But here's the catch: an illiterate battery replacement on the Redmi Note 4 can cause an IMEI reset, data loss, or even a hardware buildup due to a firmware conflict. In this article, we'll look at how to change the battery without risking the system, keeping all the settings, firmware and functionality of the smartphone, and how to choose which battery to take apart the phone, and what to do if you have problems charging or determining the battery level after the replacement.

Signs that the Redmi Note 4 battery needs to be replaced

Before you start screwdriver, make sure that the problem is the battery.

• 🔋 Phone's running out of power. 2-3 hours with moderate use (social networks, messengers).
• 📉 The percentage of charge “jumps”: for example, from 50% immediately drops to 15%.
• ⚡ The device is switched off when 20-30% charge and only activated from charging.
• 🔥 The battery swelled (see above the raised back cover or screen glass).
• 🛑 The phone does not turn on even after a long charge.

If at least 2-3 points match, the battery is worn out, you can check its condition through the engineering menu: enter in the dial # # # #4636##, select Battery Information and compare the current capacity with the nominal one (3800-4100 mAh for the original battery), a difference of more than 30% is a direct signal to replace.

⚠️ Attention: Bloated battery is dangerous! It can damage the board or even ignite. If the phone case is deformed, don't delay replacing it.

What battery to choose for Xiaomi Redmi Note 4

The original Redmi Note 4 batteries are no longer in production, but there are some decent ones on the market, and the key is to avoid counterfeiting with understated capacity.

Recommended brands-analogues: ZMI (official partner Xiaomi), Baseus, Remax. Check the availability of the charge controller and thermistor - without them, the battery will not correctly determine the level of charge. The cost of a quality battery: 800-1500 rubles.

Preparing for replacement: tools and safety

To disassemble the Redmi Note 4, you will need:

• 🔧 Screwdriver kit: cross-haired (PH00), flat-plastic mediator.
• 🔥 Hair dryer or thermo-air station (for softening glue).
• 🧲 Screen removal suction cup (optional).
• 📦 New battery with double-sided tape.
• 🔌 Multimeter (to check the voltage).

Important: before disassembling, completely discharge the phone (before turning off automatically), this minimizes the risk of short circuits, and back up the data — although the battery replacement should not affect memory, accidents cannot be ruled out.

Turn off the phone and remove it SIM-map|Take a picture of the location of the plumes|Prepare the workplace (clean surface, good lighting)|Check the new battery with a multimeter (voltage 3.7-3.85 V)|Wear an antistatic bracelet (optional)-->

⚠️ Warning: If you've never disassembled a smartphone, practice on an unnecessary device.The Redmi Note 4's plastic back latches are brittle - they're easy to break.

Step-by-step instructions for replacing the battery

Follow the algorithm to avoid damaging the plumes and board:

1. Remove the back cover. Heat the edge of the phone with a hair dryer (60-70 temperature).°C) for 1-2 minutes, carefully press the gaps near the volume buttons and SIM-The lid is held on the latches and glue, so don't put too much effort into it.
2. Battery shutdown. Under the lid, you'll see a battery with a black connector. Unplug it with a plastic blade (metal can close contacts!).
3. Remove the old battery. The battery is glued to the body. Pick it up around the corner and slowly pull it with the glue. If the battery is swelling, don't prick it, you're at risk of fire! Use alcohol to dissolve the glue.
4. Install a new battery. Take the protective film off the double-sided tape on the new battery and press it against the case. Connect the connector to the board.
5. Make sure all the plumes are in place, and snap the back cover. Turn on the phone and check the charge.

If the phone does not turn on after assembly, check:

• 🔌 Correct connection of the battery connector (it should "click»).
• 📱 Integrity of the display plume (sometimes it departs during disassembly).
• 🔋 Voltage on the new battery (should be 3.7-3.85 V).

Calibration of the battery after replacement

The new battery may be showing an incorrect charge level, so that the controller can be trained to:

1. Charge your phone to 100% and hold on charging for another 1-2 hours.
2. Turn off charging and use your phone until it turns off automatically (do not turn it on until it is completely discharged!).
3. Connect the charger and wait 100% without interruption.
4. Repeat the cycle 2-3 times.

If the percentage of charge still jumps, install the AccuBattery (Android) app to monitor the actual capacity, and in extreme cases, you may need to reset the battery data via the engineering menu (#36446337# → Battery Information → Reset).

💡

After replacing the battery, avoid quick charging in the first 5 charge-discharge cycles, which will prolong the life of the new battery.

Frequent problems after replacement and their solutions

Even with the right installation, there can be problems.

If the smartphone freezes on the logo or reboots after the replacement, the problem may be the firmware.

1. Download to Fastboot (hold Power + Vol−).
2. Connect your phone to your PC and execute the command: fastboot erase cache
3. Reset the device.

If this doesn’t work, you’ll need to flash it through the Mi Flash Tool (the instructions for the Redmi Note 4 are in our separate article).

💡

If after the battery change, the phone lost its IMEI or stopped catching the network, do not panic - this is treated by restoring the NVRAM through an engineering menu or firmware.

Tips for extending the life of a new battery

To make your new battery last longer, follow these rules:

• 🔌 Use an original or certified charger (5V/2A).
• 🌡️ Avoid overheating (do not leave your phone in the sun or near heat sources).
• 📴 Do not discharge the battery to 0% regularly – optimal range of 20–80%.
• 🛠️ Calibrate once every 3 months (full charge-discharge cycle).
• 🚫 Do not use your phone while charging for resource-intensive tasks (games, video).

The average life of a quality battery is 2-3 years (500-800 charge cycles).If you notice that the capacity is falling again ahead of time, check the phone for background processes (via Settings → Battery) or viruses (using Malwarebytes).

FAQ: Answers to Frequent Questions