Xiaomi Redmi 4A is one of the most successful budget models released by the Chinese giant. However, time spares no one, and even a quality lithium polymer battery loses its capacity over time. If your phone starts to quickly discharge, turn off in the cold or show a percentage of charge in a leap, then it’s time to think about replacing the energy element.
Replacing a battery on your own is not only a way to save on service, but also a way to be confident in the quality of the part you install. You don't need to be a professional engineer to do this, but you need to be careful, attentive and minimal in your toolkit. In this article, we'll take a look at each step of the process in detail so you can get your gadget back to life.
Before you start, it's important to understand that any repairs are risky, that doing the wrong thing can damage the plumes or even burn an old battery, but if you follow the safety precautions and the algorithm, the recovery will be successful, and let's get ready for the procedure and learn the nuances of the device of this model.
⚠️ Warning: If the old battery is swollen and inflated, do not press on the screen and back cover.Mechanical damage to the bloated battery can lead to the ignition of the electrolyte.
Diagnostics of battery status and choice of replacement
Before you disassemble the device, you should make sure that the problem lies in the physical wear of the chemical element. Software failures can also distort the readings of the sensors. Check the usage statistics in the Settings → Battery menu. If the discharge schedule looks smooth, but the operating time has decreased significantly, this is a sure sign of degradation.
When choosing a new battery for the Redmi 4A, it is critical to pay attention to the labeling and capacity.The original model has a capacity of 3120 mAh. The market is crowded with fakes that can have a real capacity of half the declared one. Look for models with the BM47 code or compatible counterparts from proven manufacturers such as Nohon or Cameron Sino.
Here are the main signs that replacement is needed:
- 📉 The smartphone turns off when charged 15-20%.
- 🔋 Appearance of a characteristic hump on the back cover or detachment of the screen.
- ⚡ The phone charges up to 100% in 20 minutes, but only lasts a couple of hours.
- 🌡️ Strong heating of the lower part of the case during the operation of simple applications.
When buying a battery, make sure to check the contacts. They should be clean, without any trace of oxidation. Also check the date of production: lithium cells age even on the shelf, so a battery that has been in storage for 3 years will be worse than the new one made a month ago.
Tools and workplace preparation required
For high-quality disassembly Xiaomi Redmi 4A standard set of screwdrivers may not be enough. the design of the phone involves the use of specific tools for work with adhesive connections and small electronics. Prepare the workplace: it should be well lit, and the surface is clean and non-conductive.
You will need the following tools:
- 🔧 Set of screwdrivers (cross-haired) PH000 flat).
- 💳 Plastic spatula (mediator) or old bank card.
- 🌬️ Hair dryer or professional hot water heater (to soften glue).
- 🧲 Magnetic mat or organizer for screws.
- 🧤 Antistatic gloves (preferably).
Pay special attention to heating. The glue that glues the back cover to the back becomes elastic when heated. Don't use open flames or gas burners -- too high a temperature can damage the screen matrix or melt the plastic elements of the case. The optimal heating temperature is about 80-90 degrees Celsius.
Before starting disassembly, be sure to turn off the device. If the phone does not respond to buttons due to deep discharge, try to give it a minimum charge so that you can perform a regular shutdown through the Completion menu, which will reduce the risk of short circuit when the battery plume is disconnected.
☑️ Ready for repair
Removal of the back cover and dismantling of components
The most difficult step is to remove the back panel carefully, and unlike the glass backed models of today, plastic is used here, but it is held on a powerful adhesive layer around the perimeter. Turn on the hair dryer and warm the perimeter of the cover evenly for 2-3 minutes, constantly moving the air flow.
After heating, insert a plastic blade into the junction between the frame and the lid, usually around the charging connector or volume button. Driving the tool along the perimeter, cutting the adhesive layer. Don't try to tamper with nails or metal objects - you risk crunching the plastic or scratching the frame.
When you take the lid off, you'll see a metal screen that covers the insides, and it's mounted with a lot of screws of different sizes, unscrew them all, and carefully remove the metal plate, and underneath it you'll have access to the motherboard and the battery.
| Component | Number of screws | Type of screw | Note |
|---|---|---|---|
| Metal screen | 10-12 pcs. | PH000 (cross) | The screws may be of different lengths |
| Payment dynamics | 2 pcs. | PH000 | Located below. |
| Battery anchorage | 0 pieces. | - | It's glue-based. |
| Screen plume | 0 pieces. | - | Connector clamp |
Now you have to turn off the battery plume, which is on top, next to the main connector of the display, use a plastic blade to gently lift the connector up. Never pull the wires, you only have to disconnect the plastic head of the connector.
Removing the old battery and installing a new one
The battery in the Redmi 4A is glued to the frame with double-sided tape. This is done for reliability, but complicates replacement. Under no circumstances do not try to rattle the battery with a metal screwdriver or a knife!
To extract safely, use a thread or heat method. If you use a thread (dental or fishing line), run it over the top edge of the battery and cut the adhesive layer with sawing movements, and you can slightly warm the body on the front side with a hairdryer to soften the adhesive.
After removing the old battery, thoroughly clean the seat of glue residues. The surface should be perfectly smooth and clean, so that the new battery lay flat and tightly on the case.
- 🧹 Remove all the remnants of old scotch.
- 🧼 Degrease the plastic battery bed.
- 🔍 Check if there is any damage to the battery.
- 📏 Make sure the new battery is the same as the original.
The new battery is usually already coated with adhesives, and if it's not there, use B-7000 strips or double-sided electronics tape, and don't use conventional superglue, which can damage the camera and the screen, and it can't withstand vibrations.
⚠️ Warning: Do not connect the battery to the board immediately after being removed from the package. 10-15 minutes at room temperature, if stored in the cold.
Device assembly and initial start
Put the new battery back in place, press it tightly all over the area. Connect the plume to the characteristic click. Make sure the connector is flat and not skewed. Now you can go back to the reverse assembly.
Put the metal shield back in place and twist all the screws. It's important not to confuse the length of the screws: too long a screw in a short hole can break through the tracks on the board or rest on the components, which will break when tightened.
Before the back cover sticker, run a test run. Press the power button. If the screen catches fire and the MI logo, you've done everything right. Let the phone charge to 100%, not turning it on, to calibrate the power controller.
Now, put a new layer of glue on your phone, or use special tapes for your phones around the perimeter of the frame, press the back cover and put rubber bands on it. 15-20 Do not turn the phone on immediately under load, let the system recognize the new battery.
Calibration and quality control of replacement
Once assembled, it is important to make sure that the smartphone correctly displays the charge level. Android can "remember" the parameters of the old worn-out battery.
Discharge the phone until it's completely turned off. Then, without turning it on, charge it. When the indicator shows 100%, hold it for another 1-2 hours. After that, you can turn on the device. If the percentage of charge has dropped, charge it again to 100% when it's off.
To check the quality of the installation, you can use special diagnostic applications, such as AccuBattery or the engineering menu. Enter the code ##6484## in the call to get into the testing menu. Select "Battery Check" and make sure that the battery status is "Good" and the voltage is within the normal range (3.7V - 4.2V).
If you notice that the phone is warming in the battery area even in a simple one, immediately turn it off and check the density of the plume. Bad contact causes heating and voltage surges, which is dangerous for the motherboard.