Xiaomi Redmi 4 is deservedly considered one of the most reliable devices of its time, but even the highest quality lithium polymer battery loses capacity over time. If your device stops holding charge, turns off 20-30% or swells up, lifting the back cover, then it's time to replace the battery. This is a common problem for gadgets released several years ago.
Replacing your battery on your own is a real opportunity to save money and extend the life of your favorite gadget for another couple of years, a process that requires care, but is not overly complicated if you have the right set of tools and a clear understanding of the sequence of actions. In this article, we will discuss each step in detail.
It's worth noting that the Redmi 4 has its own design features that make it different from the more modern monoblocks, and there's no perimeter adhesive, which makes it much easier to access the insides, but the display plumes and connectors need to be handled carefully. Let's get ready for repair.
Diagnostics and selection of a new battery
Before you start disassembling, you need to make sure that the problem lies in the power source. Sometimes the failures cause software errors or a malfunction of the charge controller on the motherboard. If the phone warms in the area of the camera even in a simple one, this can indicate an internal short circuit in the cell.
When choosing a new battery, it is important to pay attention not only to the capacity, but also to the manufacturer.The market is full of cheap copies that can not only quickly degrade, but also damage the electronics of a smartphone. The original battery for Redmi 4 is usually labeled BM46 or similar, depending on the specific modification (Prime, Pro).
⚠️ Note: Buying a battery without packaging (OEM), Make sure to check the contacts, they should be free of oxidation or mechanical damage, and the date of production should be fresh.
The manufacturer's stated 4,100 mAh capacity is also important, but the actual capacity of cheap ones is often less than 2,000 mAh. Visual inspection of the thickness of the battery is also important: the originals are not overly thin or, conversely, bloated.
- 🔋 Original: High reliability, accurate compliance with dimensions, stable operation of the controller.
- 📉 Quality copy: Acceptable capacity (about) 80-90% normal operation, but less cycle life.
- 💣 Cheap analogue: Real capacity is severely understated, risk of bloating after a month of use, lack of protection.
If you're in doubt, it's better to pay for a proven brand than to change the battery again in six months, and the resource of the item directly affects the usability of the device as a whole.
Tools and workplace preparation required
Successful repairs require a minimal set of tools that many home craftsmen have or are easily bought in specialty stores, the main requirement is cleanliness and good lighting, dust and villi can get under the display or into connectors, which will lead to poor build.
You will need a thin plastic spatula (mediator) to open the body, a set of cross screwdrivers (usually PH00 or PH000), tweezers and a sucker. It is also highly desirable to have a thermophen or at least a hair dryer to soften the fixing elements, although in Redmi 4 they are minimal.
☑️ Checking readiness for repair
Space organization is critical. The screws in modern smartphones can be long and threaded, and if you screw a long screw into a hole for a short one, you can punch through the motherboard or damage the internal plumes.
Use a magnetic mat or just a piece of paper that you can schematically draw the screws on, which will help you avoid confusion when you reassemble. Don't forget about antistatic safety: touch the grounded object before you work to remove the static charge from the body.
The process of disassembling the body Xiaomi Redmi 4
Unlike many modern models, the Redmi 4 has a removable back cover, which is a huge plus for maintainability. However, underneath it hides screws that fix the plastic frame. SIM-memory-card.
Carefully apply the back cover with your nail or plastic spatula in a specially designated recess at the bottom of the body. Move around the perimeter, snapping the latches. Do not use excessive force to avoid breaking the plastic locks.
Once you take the lid off, you'll see a battery and some screws under the plastic lining at the bottom. Unscrew all the screws you can see. The number can vary depending on the board revision, but they're usually around. 10-12 Be careful, some screws may be hidden under stickers.
⚠️ Attention: When removing the plastic frame-layer, proceed carefully. Under it are plumes of the display and touch screen, which can easily be damaged by sloppy movement of the tool.
Now you have to disconnect the plumes, and to do this, gently lift the protective metal plates of the connectors (if any) and snap the connectors with a plastic blade, and the movement should go from the edge of the connector to the center, not across.
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Take a picture of all the screws and plumes before they're turned off, and that helps you remember which screw to twist when you build them.
Once all the connectors are turned off, you can completely remove the plastic frame, allowing access to the motherboard and the bottom of the case, and now the path to the battery is clear.
Removing the old battery and installing a new one
In the Redmi 4, the battery is not usually glued to the same level as in glued monoblocks, but can be held on double-sided tape. Use a suction cup or gently apply the edge of the battery with a spatula to extract it.
Do not try to pull the battery by the wires or connector, this will lead to a break in the contacts and the inability to charge the device. If the battery is swollen, treat it with extreme caution, so as not to damage the shell and cause a chemical reaction.
Clear the seat of the residue of old glue or tape. The surface must be flat and clean so that the new battery will lie tight and not hang around inside the case. Install the new power unit by combining the connector with the reciprocating part on the board.
Before the final assembly, the first connection is recommended: connect the battery plume to the board and press the power button. If the phone responded (vibration, Mi logo), then the connector is connected correctly and the battery is working.
| Work segment | Tool. | Risk of error | Implementation time |
|---|---|---|---|
| Removal of the back cover | Plastic spatula | Latch break | 1 minute |
| Screwing of screws | Screwdriver PH00 | Loss of screws | 3 minutes. |
| Shutting down the plumes | Plastic spatula | Connector explosion | 2 minutes. |
| Battery replacement | Suction/Scape | Puncture of the element | 5 minutes. |
Device assembly and initial start
Once the test is successful, you can start the final assembly, make sure that all the plumes are in their channels and not be framed, and an improperly laid plume can lead to a broken touchscreen or artifacts on the screen.
Twisting all the screws in the plastic frame. Don't drag them, the plastic in the old devices becomes brittle and can crack, and even diagonal twisting will help avoid distortion.
Set the back cover, starting at the top (near the camera) and snapping the locks around the perimeter until the characteristic click. Check if there are gaps between the lid and the frame. The gaps may indicate untwisted screws or debris.
What to do if the phone is not turned on?
Turn on the device and check the basic functions: touchscreen, speakers, microphone and cameras. Make sure that the system correctly displays the level of charge.
Calibration and operating recommendations
After installing the new battery, it is recommended to conduct a calibration procedure, which will help the system correctly display the percentage of charge. To do this, completely discharge the phone before automatically turning off, and then charge it to 100% when turned off.
For the first few charge-discharge cycles, try not to interrupt the process. This will allow the battery controller to "learn" and remember the actual cell capacity. Modern Li-Pol batteries have no memory effect, but calibrating the controller is useful.
To extend the life of a new battery, avoid deep discharges to zero and overheating the device. Do not leave the phone charging under a pillow or in the sun. The optimal charge range for long-term storage and use is 20% to 80%.
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Proper calibration in the first days of use significantly improves the accuracy of displaying the charge level and prolongs the life of the new battery.
Compliance with simple rules of operation will allow your Redmi 4 to serve faith and truth for a long time. Repairing with your own hands is not only saving, but also confidence in the quality of the work performed.