Xiaomi Redmi 7A has proven to be a reliable budget device that can work for a long time without recharging. However, over time, regardless of careful handling, the capacity of any lithium-ion battery inevitably decreases, leading to rapid discharge and sudden shutdowns of the gadget.
If you notice that your phone stops holding charge, warms up while working or turns off at 20-30% charge, it’s probably time to replace the energy cell.Self-replacing the battery with a Redmi 7A is a very real task for a home craftsman, which will save money and extend the life of the device for several more years.
In this article, we will discuss in detail the process of dismantling the back cover, turning off the plumes and installing a new battery, paying special attention to precautions, since working with electronics requires accuracy and understanding of physical processes.
Diagnostics of battery condition and workplace preparation
Before you start disassembling your smartphone, you need to make sure that the problem lies in the wear of the battery chemistry, and not in a software failure or malfunction of the power controller. To begin, carefully examine the case of the device: if you notice that the back cover has moved away or bloating on the screen, this is a sure sign that the battery is inflated and requires immediate replacement to avoid damage to the display.
It's also worth checking the usage statistics in the settings menu. If the discharge graph shows sharp jumps, such as a drop from 40% to 5% in a few minutes, this indicates a loss of capacity. It's important to calibrate before repair to eliminate programmatic errors in charge display.
- 🔋 Perform a full charge and discharge cycle: bring the phone to 0% off, then charge to 100% when off.
- 📱 Use monitor apps like AccuBattery to evaluate real-world health capacity versus claimed capacity.
- 🔍 Visually inspect the charging connector for oxides or contaminants that may mimic battery problems.
To make a good replacement, you need to organize a workplace with good lighting and no static electricity, and it is best to use an antistatic mat or just work at a wooden table, having previously wiped it with a wet cloth to remove dust.
⚠️ Warning: Never start disassembling if the phone's charge level is below 25% or above 75%.A charge of around 50% is considered ideal, as a fully charged battery is more prone to fire if damaged, and a deeply discharged one may not start the phone for check after repair.
Essential tools and supplies
The success of the battery replacement operation depends on the quality of the tool used. Xiaomi Redmi 7A has a plastic case that is attached to latches and adhesive layer, so the toolkit will be standard for modern smartphones, but will require a certain accuracy.
You will need a special screwdriver with a cross-shaped slime, as the screws in this model have a standard head.Do not try to use a knife or other sharp objects to unscrew the screws, as this can lead to the hat breaking and complicate the process.
☑️ Repair toolkit
Special attention should be paid to the choice of a new battery. The market is oversaturated with fakes, so it is important to buy original components or quality analogues from proven brands such as Nohon or Deji. The original battery for this model is marked BM3E and has a capacity of 4000 mAh.
The new battery and back cover will require special glue to fix. Professional repairs often use B-7000 glue, which remains elastic after drying and allows the case to be reopened if necessary. Double-sided tape is less reliable, but also applicable for budget repairs.
⚠️ Note: It is strictly forbidden to use superglue (cyanacrylate) to glue the battery or cover. Superglue pairs can damage the camera and display, and the glue itself becomes fragile and can crumble, ceasing to hold the body, or, conversely, glue the components tightly together, making future repair impossible.
Removal of the back cover and dismantling of components
Beginning of Redmi's showdown 7A It requires care, because the plastic cover can crack if handled carelessly. SIM-cards to remove internal stress from the structure of the body.
Then you have to unscrew the two visible screws, which are located at the bottom of the back panel on the sides of the charging socket, and once they're removed, the lid will not be removed by itself, because it's held on a powerful adhesive layer around the perimeter and in the center.
To separate the cover, it is best to use a suction cup and a plastic spatula. Heat the edges of the body with a hair dryer to about 60-70 degrees (hold 1-2 minutes) to soften the glue. Don't overheat one point for too long so as not to deform the plastic.
What to do if the lid is not removed?
When you take the lid off, you'll see the inside of the smartphone, and the first thing you do is turn off the battery plume to turn it off, and then you unscrew the plastic bar that covers the main connectors of the display and motherboard.
- 🔧 Carefully disconnect the main camera plume if it interferes with access, though on Redmi 7A The camera often doesn’t require a complete dismantling.
- 🔌 Turn off the display plume and touchscreen using a plastic shoulder blade so as not to damage the contacts.
- 📷 Remove the main camera module if access to the battery screws is blocked (depending on the board revision).
They can't be pulled by wires, just by rigid connectors, and any careless movement can lead to the breaking of tracks and the need to replace expensive modules.
Removing the old battery and installing a new one
The most difficult step in replacing the battery on the Xiaomi Redmi 7A is to remove the old battery, as it is glued to the frame of the case with double-sided tape around the perimeter and in the center.Manufacturers do this for safety so that the battery does not hang around inside, but this complicates repairs.
Do not attempt to rattle the battery with a metal screwdriver or knife. A puncture of a lithium-ion cell will cause an instant fire or explosion with the release of toxic gases. Use plastic cards, fishing line or special hoods to safely extract.
One effective method is to use floss or floss, and you can thread the top edge of the battery (from the camera side) and you can seep it, and you can gently cut the adhesive layer, pressing the thread against the body, not the battery itself, and it takes time, but it guarantees safety.
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If the old battery is overblown, be very careful, don't push it or bend it, and you can carefully paste cross-cotch tapes on it before you take it out to fix the shape and prevent it from further dissecting when you heat it up.
Once the old element is removed, you need to thoroughly clean the seat of the residue of old glue and tape. Use isopropyl alcohol or a special glue cleaner. The surface should be perfectly smooth and fat-free for the new battery to be reliably fixed.
The new battery is installed in the case, pre-applied on its back a new layer of glue B-7000 or pasting bilateral tape. Do not apply glue directly to the battery itself, it is better to apply it to the case or on the protective film of the battery (if it is removable), giving the glue a little dry to a sticky state.
Connect the new battery plume to the motherboard, make sure the connector is up before you click and is fixed with a pin down bar, and you can now test the performance by turning on the phone briefly without fully assembling the case.
Assembly of the device and check of performance
If the phone is on and shows the correct percentage of charge, you can start the final assembly, which requires careful attention, because you need to properly stack all the plumes so that they are not clamped by the case.
Put a plastic safety bar over the connectors and twist all the screws. Make sure that no screw is left over, because every detail matters in the design of your smartphone. Then plug in the display plume and the cameras if they've been turned off.
| Assembly stage | Action. | Important nuance |
|---|---|---|
| Setting up the bars | Tailing of metal and plastic screens | Do not pull screws, the thread in the plastic easily breaks off. |
| Connecting plumes | Connection of display, touch screen, battery | The train should lie flat, without breaks and tension |
| Fixing the lid | Applying glue and pressing the back panel | Use rubber harnesses or a load for 1-2 hours to grasp |
| Final check | Incorporation and test of functions | Check the sensor, speakers and charging |
To fix the back cover, apply a thin layer of glue around the perimeter of the frame. Spread it evenly and let it dry for 2-3 minutes. Then apply the lid gently, combining all the holes, and press it tightly around the perimeter.
For better grip, it is recommended to fix the body with rubber harnesses or put a small load (for example, a book) on top for 1-2 hours. Do not turn on the phone and do not expose it to loads until the glue is completely dry.
First start and calibration of the new battery
After successful assembly and drying of the adhesive, the correct initial battery activation is required. Modern lithium polymer batteries do not require long "pumping" like old nickel batteries, but initial calibration of the power controller will be useful.
Turn on your smartphone and wait for the system to load. If your phone is charging less than 20 percent, charge it with the original cable and power supply. Don't use your phone on the first charge, let it dial 100 percent safely.
After reaching full charge, leave the phone on charging at another time. 30-60 Then turn off the charger and use the smartphone as normal until it turns off due to the discharge. 100% non-interrupted.
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The full charge-discharge cycle (0% → 100% → 0%) helps the power controller accurately determine the real capacity of the new battery and correctly display percentages.
In the early days of operation, pay attention to the behavior of the device. It should not heat up much in standby mode or on easy tasks. If you notice abnormal heating in the battery area, immediately turn off the device and check that the plume is correctly connected.
Frequent errors and safety measures during repairs
Electronics repairs are always risky, and battery replacement in the Redmi 7A is no exception. The most common mistake of beginners is neglecting to shut down the battery before disconnecting other plumes. This can short-circuit and burn out the power chains on the motherboard.
Another common problem is damage to the touchscreen plume or display when the back cover is not removed neatly. The plastic cover can move unevenly, and if you pull the phone sharply at this point, the plume going to the side of the case can break.
- 🚫 Do not use metal tools to pick inside the case near the battery.
- 🚫 Do not leave your phone unattended immediately after replacement to monitor possible heating.
- 🚫 Do not throw the old battery in a regular garbage can, hand it over to a special recycling point.
Also worth mentioning is the waterproof. Xiaomi Redmi 7A does not have full waterproof, and after dismantling the leakage is broken permanently. After repair, the phone becomes even more vulnerable to water and dust, so avoid using it in high humidity conditions.
⚠️ Warning: If the phone doesn't turn on after you replace the battery, don't rush to disassemble it again. 15-20 Sometimes it takes the power controller a while to wake up and start consuming power after a deep discharge or shutdown.