Modern smartphones, including popular Xiaomi models, are designed to minimize the space inside the case, making the process of dismantling internal components, especially batteries, quite a challenge for an untrained user. If your Redmi 7 device begins to quickly discharge or suddenly turn off, most likely, the resource of the chemical battery is exhausted and needs to be replaced.
The battery removal process in this model is complicated by the fact that it is securely glued to the frame with a special adhesive compound. Careless actions can damage the plumes, the screen or even blow up the battery when exposed to physical stress, which is why it is important to strictly follow the algorithm of actions and use a specialized tool for safe work.
In this article, we will discuss in detail how to properly prepare the device, what tools will be required and what nuances exist when working with adhesive base. A competent approach will allow you to extend the life of a smartphone without the risk of damaging other expensive components of the motherboard or display module.
Tools and workplace preparation required
Before any manipulation of the insides of a smartphone, you need to ensure a clean, well-lit workplace. Dust and static electricity are the enemies of electronics, so it is best to work on an antistatic mat or a clean wooden surface. You will need a set of precision screwdrivers, including a Phillips cross #00 and a flat one for snapping plumes.
It can be a professional separator, but in the home, you often use a dryer or even a heating pad, although temperature control is difficult. overheating can damage OLED-matrix or melt plastic elements of the body, and underheating will not soften the glue.
- 🛠️ Set of screwdrivers (cross, flat, Torx star if necessary).
- 🔥 Hair dryer or heating platform for softening glue.
- 💳 Plastic blades and mediators for opening the body.
- 🧲 Magnetic screw-sorting mat.
- 🧴 Isopropyl alcohol or special solvent of glue (B-7000).
Also, be sure to prepare a suction cup for removing the back cover and tweezers with dielectric tips. The use of metal tools inside the case is strongly discouraged, as you can accidentally close contacts on the board. All tools must be serviceable and clean, so as not to introduce contamination into the device.
Primary safety measures and de-energization
The first step before disassembly is to turn the device off completely. Don't rely on sleep or hibernation, the system must be completely powered down. If the smartphone screen is broken and does not respond to touch, try pressing the power and volume button to force the restart, then wait for the shutdown.
⚠️ Warning: Never start disassembling if the battery is above 25%. Damage to the lithium polymer battery when charged can cause a thermal reaction, fire or even explosion.
After turning off, remove the tray for SIM-This is a standard procedure that prevents slots from breaking when the case is bent during dismantling. In the Redmi 7 model, the tray is combined, so make sure you don't lose small memory cards when you remove them.
Check the integrity of the back cover. If there are cracks on it, heating can lead to their expansion and complete destruction of glass or plastic, in which case it is recommended to pre-glaze the cracks with transparent tape to hold the fragments together during the removal procedure.
Removal of the back cover and access to the board
The back of the Xiaomi Redmi 7 is mounted on a two-part adhesive around the perimeter of the body. To start, warm the device evenly with a hairdryer. Keep the heat source at a distance of 3-5 centimeters and constantly move it so as not to overheat one point. The optimal heating temperature is about 80-90 degrees Celsius.
After heating (usually 2-3 minutes), place the suction cup at the bottom of the back cover, closer to the center, but not on the camera. Pull the suction cup up, creating a slight voltage, and insert a thin plastic blade into the resulting gap. Do not use force if the lid does not respond - it is better to warm the case again than break the glass.
We shovel along the perimeter, carefully cutting the adhesive layer, pay special attention to the corners and areas around the main camera module, as there is often a thicker layer of glue, and when the lid is completely separated, put it in a safe place, away from the edge of the table.
- 🌡️ Warm up the perimeter evenly, avoiding the camera lens area.
- 🔪 Move the blade parallel to the plane of the body so as not to damage the display.
- 👀 Visually monitor the position of the plumes under the lid before full removal.
When you take the lid off, you'll see a plastic frame covering the main board and the battery, which is also attached to the screws and glue, and you'll carefully unscrew all the visible screws, remembering their location, because they can have different lengths and threads.
Dismantling the protective frame and disconnecting the plumes
The plastic cover that hides the internal components, in the Redmi 7, is a stiffening reinforcer, and it's mounted with a lot of screws around the perimeter and in the center, and you use a magnetic mat to put the screws in the order you've been twisting them, which makes it much easier to build.
After removing all screws, carefully apply a plastic blade to the frame, and there may be adhesive layers, especially in corners, and act slowly, avoiding the plumes that may be underneath or glued to the edges of the frame.
Before you take the frame off completely, you need to disconnect the main battery plume from the motherboard, which is a critical step to ensure that you keep it safe. Find the battery connector, which is usually located on the top of the board or on the side, and bend it gently with a plastic tool.
☑️ Checklist before removing the battery
Now you can take the entire safety frame off, and underneath it you can access the battery, the vibrator, the bottom charger, and inspect the space for any dust or traces of moisture that may have entered the space before.
Technology of safe recovery of the battery
The battery in Redmi 7 is glued to the middle frame or back cover (depending on the build modification) is quite firmly. You can't just pull it out like that, it will deform the battery housing, which is strictly forbidden. Removal will require reheating the battery area through the open space or removing the middle frame if the design allows.
Heat the battery area with a hair dryer for 3-5 minutes. The glue should become soft and viscous. After heating, take a thin plastic card or a special spatula and gently tuck the edge of the battery. It is best to start at the bottom, where the connector usually is.
Use isopropyl alcohol during the separation process. Drop a few drops under the edge of the battery and wait for the liquid to penetrate the adhesive layer. This will greatly facilitate the process and reduce the risk of rupture of the battery case. Avoid using metal objects that can puncture the shell.
⚠️ Warning: If you smell chemicals or see smoke, stop working immediately, take the device out into the open and place it in a non-combustible container.
Move the shoulder blade forward, gradually separating the battery from the base. Don't try to lift it over one edge, it will create a point of tension that can lead to a break. Act evenly throughout the area.
What to do if the battery is blown?
Installation of a new power supply and assembly
After successfully removing the old battery, you need to thoroughly clean the seat of the old glue residue. Use a napkin dipped with alcohol to degrease the surface. The new battery should fit perfectly to the case without gaps and distortions.
Apply a new layer of glue. This is great for special adhesive tapes for electronics or liquid glue B-7000. Apply the glue with a thin layer around the perimeter and one strip in the middle, avoiding getting on the contacts and the camera. Let the glue dry a little (1-2 minutes) before installing the battery.
Set the new battery tightly pressed over the entire area, plug the plume into the characteristic click, make sure the connector is up straight and not skewed, and then you can start to reverse assemble, installing a plastic frame and twisting the screws.
| Parameter | Old battery | New battery | Norma. |
|---|---|---|---|
| Capacity (mAh) | 3800-4000 | 4000 | ±5% |
| Voltage (V) | 3.85 | 3.85 | Standard |
| Thickness (mm) | 4.5+ | 4.0-4.2 | No bloating. |
| Weight (g) | ~45 | ~48 | Original |
Swirl the screws cross-cross to ensure that the frame fits evenly. Don't pull the screws, the plastic in Xiaomi is quite fragile and can crack. Once the frame is assembled, install the back cover, pre-applying a new layer of glue around the perimeter.
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After the battery is replaced, don’t turn the phone on immediately, let the glue gain initial strength within 30-60 minutes, and complete polymerization in 12-24 hours.
Primary start and calibration
Once the device is finally built, you can turn it on, and the first run can take longer than usual, because the system checks for new components, and if the phone is on and shows the right charge level, then the replacement has been successful.
However, the power controller could remember the parameters of the old, worn-out battery. To correctly display the percentages and operating time, it is recommended to calibrate the system. To do this, completely discharge the phone before turning off, then charge it to 100% when turned off.
Repeat the charge-discharge cycle 2-3 times, which will help MIUI software re-determine the actual capacity of the battery installed, and will provide more accurate predictions of battery life in the future.
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Proper calibration of the battery after replacement is the key to accurate display of the percentage of charge and stable operation of the smartphone power system.
Possible problems and solutions
There may be unexpected situations during the replacement process, such as the phone may not turn on or write "Battery unknown" often due to poor plume contact, and try to gently reconnect the connector to check for oxides or contaminants.
If the phone turns on but it discharges quickly or warms up, you may have a poor battery, the market is filled with fakes that don't match the declared performance, and then you need to re-replace the battery with a certified battery.
It's also possible to have a scenario where the fingerprint scanner or the vibrator stops working, which means that the train of the corresponding module has been damaged or forgotten during assembly, and you have to take the device apart again and check all connections.