How to replace the battery on the Xiaomi phone: a step-by-step guide

Xiaomi smartphones are famous for their high performance and excellent value for money, but even the most reliable lithium-polymer batteries lose their capacity over time. When the phone starts to run out in half a day or suddenly shut down at 20% charge, it’s time to think about replacing the power unit. It’s not just a matter of comfort, but also the safety of your device, as a bloated battery can damage the display or motherboard.

Replacing your battery by yourself with a Redmi or Poco is a very easy task for someone with minimal electronics and neatness skills. You don't have to carry your gadget to a service center and overpay for a master's job if you're willing to study the process and purchase quality components. In this article, we'll look at all the nuances of diagnosis, selection of a new battery and the installation process itself.

But you have to understand that modern smartphones are very tightly assembled, and access to internal components requires caution. Wrong actions can damage the plumes or tear the screen, so before you start work, you need to soberly assess your strength and prepare the workplace. If you are willing to take risks and save money, let's get started with preparation.

Diagnosis of battery condition and signs of wear

Before disassembling the case, you need to make sure that the problem lies in the physical wear of the chemical element, and not in a software failure or faulty power controller.The first and most obvious sign is a rapid discharge of the device even in standby mode. If your Xiaomi Mi or Redmi Note discharges from 100% to 0% in 3-4 hours of moderate use, this is an alarm.

Another critical symptom is the spontaneous shutdown of the phone when there is a charge, for example, at 30-40%, which indicates that the nominal voltage of the battery has fallen below the permissible threshold under load.

For more accurate diagnostics, you can use built-in system tools or special applications. In the MIUI engineering menu or through third-party snails like AccuBattery, you can see the real capacity and health (Health) of the battery. If the wear exceeds 25-30%, replacement becomes inevitable for normal operation.

• 🔋 The phone is discharged to 0% in less than 4 hours of active screen.
• ⚡ The device is switched off when the residual charge is 20-30%.
• 📱 There is bloating of the body or detachment of the back panel.
• ❄️ Smartphones warm up strongly even with simple tasks such as typing.

⚠️ Warning: If you notice that the back cover of the smartphone has started to bend or the screen has risen on one side, immediately stop charging the device.

It is also important to rule out software causes such as background processes or viruses that can land the battery. Try restarting the phone in safe mode and checking the power statistics in the Settings → Battery and Performance menu. If there are no suspicious applications and the power consumption is abnormally high, the problem is hardware.

Choosing a high-quality battery: original or analog

The mobile parts market is full of supplies, and it can be difficult to choose a really high-quality battery. For Xiaomi devices, there are three main categories of batteries: original (OEM), quality (Premium Copy) and cheap discarded goods. Understanding the difference between them will help you avoid re-repairing in a month.

Original batteries are brand-named and often come in special packaging with protective holograms and QR-They have declared capacity, meet all security standards, and have a built-in controller that communicates properly with the motherboard, but they can be expensive and the risk of being counterfeited is high.

High-quality analogues from well-known component manufacturers (for example, Nohon, Deji, Remax) are often equal to the original, and sometimes even surpass it in real capacity. These batteries have a reliable controller for protection against overheating and overcharging. Cheap “nouneim” options are better bypassed: they can not hold a charge, warm up or fail in a couple of weeks.

When buying, pay attention to the date of production: lithium polymer cells age even without use. Do not take the battery if it has been more than 1.5-2 years since its release. Also check the presence of protective film on the contacts and the quality of the marking print - the original text is clear and does not erase with a finger.

💡

Buy batteries only in specialty stores with a guarantee or at official sites of the brand. Avoid markets and dubious shops where you can sell a restored old element under the guise of a new one.

Tools and workplace preparation required

Successful battery replacements on Xiaomi and Poco smartphones require a minimal set of tools, often sold as ready-made repair kits, the main requirement for the site is good lighting and no static, and work better at a table with a hard surface, covered with an antistatic mat or just a clean sheet of paper.

You'll definitely need a hair dryer (construction or household at maximum power) to soften the glue that holds the back cover. Modern phones are assembled without screws on the case, so heating is the only way to open them without damage. You also need suction cups, mediators (plastic blades) and thin metal blades for neat opening.

To work with the internal components, prepare a set of screwdrivers, mainly cross (PH00, PH000) and Torx (T2, T3), as screws can be different. Don't forget about tweezers to extract small parts and plumes, and isopropyl alcohol to clean surfaces of old glue. Use only 99% isopropyl alcohol, as it evaporateses quickly and does not conduct current.

Before starting disassembly, be sure to turn off the device, which is critical to prevent short circuits that could knock out the power controller or other motherboard nodes. If the phone doesn't turn on due to deep discharge, wait 10-15 minutes on charging so it can be turned off correctly.

The process of disassembling the smartphone body

Disassembly of modern Xiaomi models begins with heating the perimeter of the rear cover. Turn on the hair dryer and evenly warm the edges of the device for 2-3 minutes, holding the nozzle at a distance of 3-5 cm. Do not overheat one point, so as not to damage the display or plastic frame, move the hair dryer in a circle.

After heating, gently insert the suction cup at the bottom of the back cover and pull up slightly, creating a small gap. Insert a plastic mediator or a thin metal spatula (pre-wrapped with tape so as not to scratch). Start slowly steering the tool along the perimeter, cutting the adhesive layer.

Be especially careful at the top of your smartphone, where the fingerprint scanner plume or the main camera is often located. Do not enter the tool too deep to avoid hitting the internal components. If the lid does not respond, warm up the problem area again with a hairdryer. After successfully detaching the lid, put it in a safe place.

⚠️ Note: Use metal tools only for the initial opening. For further work inside the case, use only plastic blades so that you do not accidentally close the contacts of the battery or damage the plumes.

When you remove the lid, you'll see the inside of the phone, and most of the time, you'll see a plastic or metal plate covering the battery and the plumes, and it's attached to the screws that you need to unscrew, and you need to fold them neatly into a separate container, because they can vary in length and thread.

Replacement of the power supply and assembly of the device

When you get to the battery, you'll see that it's glued to the body with double-sided tape. Don't try to put a metal object on the battery or push it too hard, a lithium polymer cell puncture will cause a fire, and you first need to disconnect the battery plume from the motherboard, gently lifting the connector with a plastic blade.

To remove the old element, use a special pulling tongue (if any) or a thin fishing line/dental thread. Strip the thread under the battery and move left-right "saw" the adhesive layer. You can slightly moisten the glue with isopropyl alcohol through the syringe with a needle to facilitate the process. Try not to deform the battery being removed.

After removing the old battery, thoroughly clean the seat of the glue residue. Degrease the surface with alcohol and let it dry. Apply a special glue B-7000 or T-7000 (thin layer) to the new cell (with a thin layer) or use ready-made glue strips (sticker), which often come with the kit. Set the battery, press it for a couple of minutes and connect the plume to the characteristic click.

Before you final assemble and twist the screws, check the phone's performance. Turn on the device and make sure it charges and displays the charge level correctly. If everything works, apply a new layer of glue around the perimeter of the case (if the old one has fallen into disrepair) and tightly press the back cover. Lock the phone with money bands for 1-2 hours before the glue is completely dry.

💡

The main challenge of replacing the battery is to remove the old battery neatly without damaging it and to connect the plume correctly, and the rest is mechanical and requires only care.

Primary calibration and frequently asked questions

After replacing the battery, it is recommended to conduct a calibration procedure so that the power controller correctly displays the percentage of charge. To do this, completely discharge the phone before turning off, then put it on charge when turned off to 100%. After reaching full charge, keep it charging for another 1-2 hours.

This procedure will help the system re-determine the actual capacity of the new element and adjust the algorithms. In the future, try not to bring the device to full discharge regularly, the optimal range for a long life of lithium is from 20% to 80%.