Xiaomi Redmi 7A is deservedly considered one of the most reliable “budgetary” of its time, but even legendary devices over time deplete the resource of autonomy. If your phone stopped holding a charge, turns off 20-30% or swelled, it’s time to think about replacing the battery. Self-replacement of the battery is a real way to extend the life of the gadget without going to the service center, where the cost of work can be up to 50% of the price of the device itself.
But the process of retrieving the battery in modern monoblock smartphones requires precision, the right tool and an understanding of design. Unlike older models with removable covers, here the battery is hidden under a back panel that is attached to adhesive base. Wrong actions can damage the plumes, break the glass or even ignite a damaged battery.
In this article, we will discuss how to safely open the Redmi 7A case, disable the plumes and remove the old battery to install a new one. We will look at the necessary tools, precautions and typical mistakes that beginners make when first repairing. Careful follow-up will help you avoid costly breakdowns.
Preparation of the workplace and tools
Before starting to disassemble, you need to organize a comfortable and safe space. You will need a well-lit table with a flat surface, preferably an antistatic mat, although clean wooden or plastic coating is also suitable for home repairs. on the table - the main enemy of the repairman, since small cogs are easy to lose, and their absence can lead to rattling of the body or poor fit of components.
To work with the Xiaomi Redmi 7A, you will need a minimal but specific set of tools. Without them, it is almost impossible to open the phone without damage, the main tool will be a suction cup or a special opener for heating and peeling the back cover, and you can also do without a set of screwdrivers, including a cross screwdriver sized PH00 or PH000.
- 🛠️ A set of precision screwdrivers (mandatory presence of cross and flat).
- 🔥 Hair dryer for heating adhesive base (you can use a building or powerful household appliance).
- 📱 Plastic blade or mediator for opening the body.
- 🧲 Magnetic mat or organizer for screws.
- 🧤 Antistatic gloves and tweezers (preferably dielectric).
⚠️ Note: The use of metal tools (knives, blades) to smack the back cover is strictly prohibited.You can accidentally damage the fingerprint scanner plume or break through the battery, which will lead to a short circuit.
Special attention is paid to preparing the adhesive for reassembly. The factory adhesive loses its properties after opening, and if you do not apply a new layer, dust and moisture will enter the body. You can use a special adhesive B-7000 or E-8000, which remains elastic after drying, or use ready-made adhesive frames, cut exactly for the Redmi 7A model.
☑️ Ready for repair
Safety measures when working with lithium-ion batteries
Working with power sources requires strict safety. Lithium-ion batteries installed in Xiaomi contain reactive substances that, if damaged, can react with oxygen. The main danger is a mechanical puncture of the battery housing or overheating.
If you notice that an old battery is swelling, you should handle it with extreme caution. Bloating indicates a buildup of gases inside the sealed housing. Any sharp pressure or puncture can cause the contents to ignite. So before you reach the battery, make sure you have a fire extinguisher or sand tank on hand for an emergency.
It is also important to be aware of the risk of short circuits, and even after the plume is disconnected from the motherboard, the circuit can still have residual currents, and do not allow the battery to contact metal objects, tools, or conductive table surfaces.
- 🚫 Do not try to puncture or bend a swollen battery.
- 🔥 Do not heat the battery directly with a hairdryer above 60 degrees Celsius.
- ⚡ Avoid contact of battery contacts with metal tools.
- 🧤 Work in a dry room, exclude moisture on boards.
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Before starting work, discharge the phone to a level of 5-10%. a fully charged battery carries more energy and is potentially more dangerous if damaged than a partially discharged one.
Another important aspect is static electricity. Although modern boards are protected, dry air in winter or synthetic clothing can generate discharges that can disable the power controller or other sensitive elements. Using an antistatic bracelet or periodically touching a grounded metal object will reduce this risk.
The process of heating and opening the back cover
The Redmi 7A back panel is attached to a two-part glue around the perimeter of the body, and to separate it without cracks and chips, you need to heat the adhesive layer, make it plastic. This uses a hair dryer. If there is no building hair dryer, you can use a regular household at maximum temperature, but you have to heat it longer.
Direct a jet of hot air to the ends of the device, evenly warming the perimeter. Do not hold the hair dryer at one point for longer than 3-5 seconds, so as not to overheat the display matrix or the battery itself, which is located close to the back cover. The optimal heating temperature of the case is about 70-80 degrees - the hand should feel warm, but not get burned when touching.
How much do I heat my phone?
After enough warming up, insert a suction cup at the bottom of the back cover, closer to the center, and pull up slightly, creating a small gap. In this gap, carefully insert a plastic blade or a thin mediator. Don't use the force of the jerk, act progressively, pushing the shoulder blade along the perimeter.
Move the tool smoothly, cutting off the adhesive layer. Be especially careful in the area of the fingerprint scanner, which is located on the back, and there is a thin plume that is very easy to break with the careless movement of the shoulder blade. If you feel resistance, stop and check if you hit the plume.
| Heat zone | Time of exposure | Temperature. | Risks. |
|---|---|---|---|
| Perimeter of the shell | 2-3 minutes | 70-80°C | Detachment of oleophobic coating |
| Camera area | 30-40 seconds. | Not more than 60°C | Damage to the camera matrix |
| Lower end | 1 minute | 70°C | Deformation of plastic connector |
| Upper end | 1 minute | 70°C | Damage to the auditory speaker |
When all the edges are crossed, the back cover should be easily removed. If it holds, do not use excessive force - it is better to warm up the problem area again.
Dismantling components and disconnecting plumes
When you remove the back cover, you'll see the inside of your smartphone, and immediately notice the plastic protective lining that covers the main part of the board and the battery, and it's attached with a few screws that you need to unscrew.
In Xiaomi Redmi 7A, component protection is made in the form of a plastic frame that also presses the connectors of the plumes. Unscrew all the visible screws (usually about 10-12 pieces around the perimeter and in the center).
When you remove the plastic protection, you get access to the contact groups, and the first thing you do is to disconnect the battery plume from the motherboard, which is a critical step that shuts down the device and makes it safe to do that, and then you use a plastic blade or nail to shut down, and you put the connector up from the bottom up.
- 🔌 Disconnect the main battery plume (wide connector).
- 📷 Carefully disable the main camera plume (if access is impaired).
- 🔍 Disconnect the fingerprint scanner plume (located on the cover).
- 📡 Check to turn off antenna contacts (if necessary).
⚠️ Warning: Never pull the wires of the plume, you need to turn off the connector by pressing on the connector itself or using a blade to smack the metal part of the connector, and the jerking on the wires is guaranteed to lead to a break in the tracks.
Once the battery is turned off, you can remove the top plastic bar that holds the speaker and the camera, and in some versions it can be glued, and now access to the top of the battery is open, and you should also unscrew the screws that hold the lower board if they interfere with battery recovery, but in the Redmi 7A, it is usually enough to remove the protection.
Removing the old battery and installing a new one
The battery in the Redmi 7A is glued to the middle frame of the body quite firmly. It is often impossible to pull it out by the tongue (if any) so that it is not possible, especially if the battery is swelled and pressed against the entire surface.
Carefully warm the area where the battery is located through an open frame. Don't heat too intensely so as not to damage adjacent components. After heating, try to tamper with the edge of the battery with a plastic card or a spatula. Move gradually, separating the glue over the entire surface.
It is strictly forbidden to use metal tools to tweak the battery from under the body, even a minimal puncture of the shell will lead to an electrolyte ejection and possible fire. If the battery is sitting dead, use a thin line or a special string, passing it under the battery and sawing the glue with movements left and right.
Once the old battery is removed, clean the seat of glue residues. The surface should be flat and clean. Try on the new battery, make sure it fits in size and connector. Connect the new battery plume to the motherboard before the final sticker to check the performance.
- 🧹 Carefully clean the battery bed of old glue.
- 🔋 Check the voltage of the new battery with a multimeter (should be around) 3.7-4.2V).
- 🔌 Connect the plume and check the phone's response (logo appearance).
- 🧴 Apply a thin layer of glue B-7000 on the frame or use a ready-made adhesive base.
When pasting a new battery, it is important not to overdo it with glue. The excess can leak out and damage other components or stain the back cover, apply a thin strip of glue around the perimeter of the battery bed, or use double-sided tape specifically designed for batteries.
Assembly of the device and check of performance
Once you have installed the new battery and checked it to turn on, you can start the final assembly, and the process goes in reverse: install the plastic protections, screws, plug all the plumes in, and make sure that each connector is in place with a characteristic click.
Pay special attention to the fingerprint scanner plume, which should lie flat, without any clamping or tension, if the plume is lided, the scanner will stop working or will give out errors, carefully put all the plumes in the channels intended for them.
Before you finally stick the back cover, turn on your phone and check the basic functions: charging, camera operation, speaker, microphone and, of course, fingerprint scanner. Make sure the phone sees the battery and correctly displays the percentage of charge. If everything works, degrease the ends of the case and the covers with alcohol.
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The quality of degreasing the ends before gluing directly affects the tightness of the body and protection from dust in the future.
Apply a new layer of glue or stick a finished frame. Press the back lid tightly and lock the phone with rubber rings or a load for 1-2 hours until the glue is completely dry. Don't turn the phone on actively during this period, let the chemistry polymerize.