Replacement of the battery in Xiaomi Redmi 7A: detailed instructions

Decreased autonomy is one of the most common reasons why Xiaomi smartphone owners turn to service centers, but many users prefer to solve the problem themselves. The Redmi 7A model, released in 2019, is still actively used due to its reliability and affordable cost, but over time its lithium-polymer power source inevitably loses capacity. If your device stops holding charge during the day or turns off at 20-30% charge, it’s time to think about replacing this important component.

The replacement procedure does not require specialized equipment, but requires accuracy, patience and understanding of the device of modern electronics. Inside the case of a smartphone there are many fragile elements: plumes, cameras, boards and the battery itself, which in modern models is often glued to the body. Incorrect actions can lead to damage to the display or even fire the battery, so it is important to strictly observe safety and sequence of operations.

In this article, we will discuss in detail how to safely remove an old battery from the Xiaomi Redmi 7A, what tools you will need to do this, and how to avoid typical errors. You will learn how to properly unplug the protective film, disconnect the connector and prepare a place for installing a new part.

Preparation of the workplace and necessary tools

Before any electronics work begins, a comfortable and safe workspace should be arranged, the surface of the desk should be clean, flat and well-lit so that you can see small screws and connectors, and it is recommended to use an antistatic mat or just a clean sheet of paper so that small parts are not lost or damaged by static electricity.

To do this successfully, you'll need a specific set of tools that you can buy from any radio parts store or order online. If you don't have the right screwdriver, you can lick the screw faces, and if you don't have the right suction cups, you can damage the back cover. Prepare everything you need to keep the process from interrupting at the most critical moment.

• 🔧 Set of screwdrivers: mandatory presence of cross PH000 for the screws of the body and possibly flat for neat tweaking of elements.
• 🌡️ Hair dryer or thermophen: necessary to soften the glue holding the back cover and the battery itself.
• 🎴 Plastic mediators (scapula): required to open the body without damaging the plastic and disconnecting the plumes.
• 🧲 Magnetic mat or container: for sorting screws, as they may differ in length and purpose.

Special attention should be paid to the heating source. A normal household hair dryer may not give enough temperature, so it is better to use a temperature-adjusted building hair dryer or a special heating pad for smartphones. The heating temperature should not exceed 80-90 degrees Celsius, so as not to deform the plastic elements of the case or damage the display matrix on the back side.

⚠️ Warning: Never start disassembling if your smartphone is on.Be sure to turn the device off completely by holding the power button and make sure the screen is out before you pick up the tools.

Removal of the Redmi 7A Rear Cover

The Redmi 7A has a plastic non-removable body, which means it needs to be neatly opened. The rear panel is attached perimeter to double-sided tape and glue, which hardens over time. The first step is to uniformly warm the ends of the device. Keep the hair dryer 3-5 cm away from the body and slowly move it along the seam between the frame and the cover for 2-3 minutes.

Once heated, take a plastic spatula or a thin suction cup. If you use a suction cup, attach it to the bottom of the back cover, closer to the Mi logo, and slightly pull up to create a gap. Insert a mediator gently into the gap and lead it along the perimeter, cutting the adhesive layer. Don't try to bend the lid by force, the plastic can crack, especially in the area of the camera or speaker.

Move slowly, periodically warming the cooled areas with a hair dryer. Be extra careful in the top of the smartphone, where the plumes and the main camera module are located. Once the lid starts to free off, remove the tool and remove it with your hands, pulling it up, under the lid you will see a metal protective plate covering the motherboard and connectors.

Dismantling the protective plate and disconnecting the plume

There's a metal plate underneath the back, and it's pressed with multiple screws. In the Redmi 7A, the number varies, but it's usually 8-10 screws of different sizes. Your job is to unscrew them all and put them in a prepared container, so you don't confuse the long and short ones, because when you build a long screw, it can break through the board.

Once the screws are removed, carefully remove the metal plate. It can stick slightly to the internal components, so use a plastic blade to tamper with it from the edge. Under the plate, you will access the motherboard, the main camera module and, most importantly, the battery connector. Now you need to turn off the device by turning off the battery plume.

Use a plastic blade or finger to turn off (access allows). Under no circumstances do you use metal objects such as needles or tweezers to snap the connector, as this can cause a short circuit on the board. Carefully tuck the connector from the bottom up until the characteristic click. After that, the smartphone is completely de-energized, and you can proceed to remove the battery itself.

Technology of retrieval of old battery

This is the most critical and potentially dangerous phase of the work. In the Xiaomi Redmi 7A, the battery is glued to the inner wall of the case with special adhesive strips. You can't just pull it out like that, you can damage the shell, which will cause a fire, or break the body of the smartphone. First, you need to remove the black protective sticker that partially covers the battery and fixes its position.

Use a hair dryer to warm up the bottom of the smartphone again, where the battery is located. Grease the case on the back side (through the back cover, if it is already removed, then warm directly through the metal / plastic frame) for 3-5 minutes. The glue should soften. Then take a thin plastic card or a special spatula and try to gently slip it under the edge of the battery.

Act slowly, shaking the battery from side to side. It is strictly forbidden to use metal tools (knives, scalpels) to slash the battery, since a puncture of the lithium polymer cell causes an instant chemical reaction with the release of heat and smoke. If the battery sits very tightly, you can use a thin line or a special string, pushing it under the battery with sawing movements to cut the adhesive layer.

⚠️ Attention: If you notice that the battery has swelled and deformed during the extraction process, handle it very carefully. Don't press on it or bend it. A bloated battery may burst from mechanical stress.

Once the adhesive layer is overcome, remove the old power cell. Examine the compartment: there should be no pieces of old glue or debris at the bottom. If there are sticky traces left, they can be carefully removed by winding some of the insulation onto the shoulder blade with a sticky side outwards and collecting the glue residue, or using a special liquid to remove the glue, but without fanaticism, so as not to damage the plastic.

Installation of a new battery and assembly of the device

Before you install a new battery, make sure it's labeled as original or as a quality analog. For the Redmi 7A, the battery model usually has the BN47 marking or similar, specified in the specification. Insert the new battery connector into the motherboard connector before clicking. Make sure the plume is flat and not squeezed.

The new battery is often already adhesively striped. If it's not there, use double-sided electronics tape. Don't use superglue or any other aggressive adhesives! Carefully press the battery against the case, making sure it's flat and not sticking out. Now you can put back the metal safety plate.

When you install the plate, make sure that the screws get into their holes the first time, so that you don't break the thread in the plastic pillars of the case. Wrap the screws cross-cross, gradually tightening them to ensure a uniform fit. Don't pull the screws, the plastic in this model is quite fragile.

The final step is to install the back cover. Before you do that, degrease the perimeter of the body and the lid with an alcohol napkin to remove the remnants of old glue and greasy fingerprints. If the old tape is removed completely, apply a new thin strip of special B-7000 glue or double-sided tape around the perimeter. Press the lid and lock the device with rubber bands for 15-20 minutes before the initial grasp.

First start and calibration of the battery

After assembly, take your time to turn on your smartphone. Give the glue some time to stabilize, at least 10-15 minutes. Turn on the device with the power button. If the screen catches fire and the MI logo appears, you've successfully completed the task. If the phone doesn't turn on, check the density of the battery connector fits - it may have departed during assembly.

After the first switch on, the system may show the wrong percentage of charge. This is normal for new lithium cells. To the power controller recalibrated and start correctly displaying the capacity, it is recommended to conduct a calibration cycle. Discharge the smartphone until completely turned off (0%), then charge it when turned off to 100%, and hold on charging for 1-2 hours.

• 🔋 Cycle 1: Complete discharge before switching off -> Charging up to 100% in the off state.
• 🔋 Cycle. 2: Work before 10-15% -> Charging to 100% switched-on.
• 🔋 Cycle. 3: Normal use during the 2-3 Days for the Final Stabilization of Chemistry.

Proper calibration will help the system to predict the operation time more accurately and avoid sharp jumps in the percentage of charge, for example, when the phone turns off from 15% on the screen. In the early days of use, a slight heating in the battery area is also possible - this is the process of laundry and distribution of the electrolyte inside the cells.

⚠️ Note: If after replacing the battery, the phone began to warm up strongly in downtime or quickly discharge (for example, the phone is not used for the first time). 1-2 You may have a defective battery, so you'll have to repeat the procedure with another battery.

Frequently Asked Questions (FAQ)