Smartphone Xiaomi Redmi 9A has proven itself as a reliable budget device, but over time, even the highest quality battery loses its capacity. If your device stopped holding the charge, turns off 20% or inflated, it's time to think about replacing the battery. Self-replacement battery is not only a way to save on the services of a service center, but also the ability to extend the life of the gadget, choosing a quality analogue of the original part.
The process of disassembling this smartphone has its own peculiarities related to the design of the case and the location of the plumes. It is critical to be careful when working with adhesive joints and fragile display plumes, as their damage can lead to expensive repairs. In this article, we will discuss in detail all the stages of work, from tool preparation to calibration of the new battery.
Before you start to physically affect the device, you need to make sure that the diagnosis is correct. Sometimes charging problems are not related to battery wear, but to software failures or a faulty charging port. Only if the battery is physically inflated or keeps less than 2-3 hours in active mode, it is necessary to urgently replace it. Let's consider what it will take to successfully perform this procedure.
Tools and workplace preparation required
A quality replacement of the Redmi 9A battery will require a minimum set of specialized tools. Using inappropriate items such as kitchen knives or thick screwdrivers can damage the plastic elements of the case or even puncture the battery, which is strictly prohibited due to the risk of fire.
- 🔧 Screwdriver Set: You'll need a Phillips #00 or #000 cross screwdriver to twist screws.
- 🔥 Hair dryer or thermophen: necessary to heat the adhesive base of the back cover, a conventional household hair dryer may not cope with the task.
- 🏦 Plastic mediators or suction cup: required for neat opening of the body without scratches.
- 🧴 Isopropyl alcohol and glue B-7000: Removing residues of old glue and fixing a new battery.
Organize the workspace so that it is well lit and not cluttered with unnecessary objects. Small screws have the property of "run away" and get lost, so it is recommended to use a magnetic mat or a special screw card, marking where each detail was twisted. Safety is a top priority, so make sure that there are no open fire sources in the room.
Preparing the smartphone itself is also a must-have, and before any work begins, you must turn the device off completely. If the screen is broken and does not respond to touch, try turning the phone off with a combination of the Volume+ and Power buttons, holding them for about 10-15 seconds, which will prevent short circuits when the plumes are disconnected.
☑️ Preparation for repairs
Diagnosis of the state of the battery and signs of wear
Before disassembling the device, it is worth conducting a thorough diagnosis to make sure that the intervention is appropriate. Embedded MIUI systems do not always show an accurate wear percentage (SOH), but indirect signs can tell a lot about the condition of the lithium polymer element.
⚠️ Warning: If you notice that the back cover of the smartphone has started to move away from the body or the screen is arching outward, immediately stop using the device.This is a sign of bloating battery, which can ignite when mechanically exposed or charged.
Software diagnostics can be done through an engineering menu or a special application, but they often give us errors. A more reliable method is to observe the behavior of the phone for several days, a sharp jump in the percentage of charge, for example, from 40% to 5% in a few minutes, or sudden shutdowns in the cold indicate a deep degradation of the cells.
Also, pay attention to the charging time. If you used to charge your smartphone in an hour and a half, and now it takes 4-5 hours, or, conversely, it happens instantly, but it is also used up energy quickly, this is the right signal. The table below shows the main symptoms and their probable causes.
| Symptoms. | Probable cause | Need for replacement |
|---|---|---|
| The phone is turned off at 20-30% | Low voltage under load | Tall. |
| Bloating of the hull | Gas formation within the element | Critical |
| Long charge (>4 hours) | Loss of capacity or wear of controller | Medium |
| Heating at downtime | Internal short circuit | Tall. |
The process of disassembling the Redmi 9A hull
The Xiaomi Redmi 9A disassembly begins with the dismantling of the rear panel, which is planted on a double-sided tape around the perimeter. heat the device perimeter with a hairdryer to a temperature of 80-90 degrees Celsius, evenly moving the jet of hot air. Don't keep the hairdryer at one point for too long so as not to overheat the display matrix or plastic frame.
After warming up, insert the suction cup into the bottom of the back cover, closer to the logo, and gently pull up to create a gap. Insert a plastic mediator into the resulting gap and, as you make sliding movements along the edges, snap the adhesive layer. Metal tools at this stage are best avoided so as not to damage the glass or plastic.
When the lid is removed, you'll see the internal layout, and the first thing you need to do is unscrew the screws that hold the protective plastic bar that covers the plumes. 10-12 They can be of different lengths, so remember or photograph their location.
Turning off the plumes requires special care. Use a plastic blade or nail to snap the connectors of the battery, display and main plumes. The battery plume is turned off first, which turns off the device and makes further work safe for electronics.
Dismantling an old battery and installing a new one
The battery in the Redmi 9A is attached to double-sided tape, which loses its properties over time but can hold very tightly. Under no circumstances try to rattle the battery with a metal spatula or knife - a puncture of the shell will lead to instant ignition or chemical burn.
- 🧵 Use a strong thread or a special plastic card: stretch them under the battery and sawing movements separate the glue.
- 🌡️ Preheating: If the battery is sitting in a dead grip, slightly warm up the area under it with a hair dryer (no more than 60 degrees).
- 🧹 Cleaning the seat: after extraction, remove all remnants of old glue with alcohol and a napkin.
When installing a new battery, make sure it is fully consistent with the original model (usually a BM47 or analogue). Connect the new battery plume to the motherboard before clicking, but don't stick it permanently. Turn on the phone to check the health: the Mi logo and charging indication should appear.
If the device is on and it shows the correct percentage of charge, you can start fixing. B-7000 on the case or use ready-made adhesive strips (double-sided scotch), which often come complete with new batteries. 15-20 minute.
Device assembly and initial start
The assembly is done in reverse disassembly. Put a plastic safety bar in place and twist all the screws. Make sure the plumes are flat and not clamped. Pay special attention to the plume of the main camera module and display, which must be fixed by the connectors to the point.
Before closing the back cover, it is recommended to check the operation of all modules: cameras, speakers, microphone and vibrator. If everything is working correctly, degrease the body perimeter with alcohol and apply a thin strip of glue B-7-000 or install a new adhesive frame. Press the lid tightly around the perimeter and lock the device with rubber bands for 30-40 minutes.
After assembly, turn on your smartphone and wait for the system to fully load. The first few charge-discharge cycles may not be correct, as the power controller needs time to calibrate the new capacity. Calibration usually occurs on its own after 2-3 full cycles.
Battery calibration and operating recommendations
After replacing the battery with Xiaomi Redmi 9A, the system may misrepresent the charge level. To correct this, perform a calibration procedure. Discharge the phone until completely turned off (0%), then charge it when turned off to 100%. After reaching 100%, hold on charging for another 1-2 hours.
Follow the rules for lithium polymer batteries to extend their lifespan, avoid deep discharge to zero and do not keep the device constantly on charge after reaching 100%, the optimal range for a long battery life is from 20% to 80%.
⚠️ Warning: Do not use your phone while charging if it is very hot.High temperature is the main enemy of battery chemistry, it accelerates degradation and can lead to bloating.
Also worth checking is the power saving settings in MIUI. Turn off auto-runs of unnecessary applications and limit background activity to keep the new battery as long as possible. Update the system regularly, as manufacturers often release patches that optimize power consumption.