If you have Xiaomi Redmi 3 stopped holding the charge or turned off on 20-30%, Now, it's time to think about replacing the power source, and this smartphone, which came out a few years ago, was originally powered by a capacious battery. 4100 mAh, which was a remarkable performance for its time, but lithium-ion cells degrade over time, losing their capacity and ability to give current under load.
Recovery is a neat process, but it's easy to do at home with a minimum set of tools. You don't have to take your phone to a service center if you're willing to be slow and careful. In this article, we'll look at all the details of the procedure, from the selection of the spare part to the final calibration of the system.
It is worth noting that the design of the Redmi 3 has its own characteristics, which distinguish it from the more modern models with non-removable covers and adhesive frames. It uses a combined method of attachment, which requires a specific approach to opening. Wrong actions can damage the plumes or even fire an old battery, so follow the instructions Step-by-step.
Diagnosis of the battery condition and selection of components
Before you start disassembling, you need to make sure that the problem lies in the physical wear of the chemical element, and not in the software failure or malfunction of the power controller. The symptoms can be several: bloating, rapid discharge in standby mode or sharp jumps in percentage of charge. If the phone is lying on the table and loses 10-15% in an hour without use, this is a sure sign of needing to replace.
It's critical to get the right battery model. There are lots of copies on the market that may not only solve the problem, but also damage the device. The original power cell for Redmi 3 is labeled BM46. When you buy, pay attention to the availability of holograms, the quality of the logo print and, of course, the price - too cheap options are almost always fake.
⚠️ Warning: Never use batteries with visible damage to the body, traces of contact oxidation or bloating.Installation of a defective battery may short-circuit and cause the motherboard to fail.
When choosing a new part, consider the type of connection. This model uses a standard connector, but the length of the plume and the location of the contacts may vary slightly from one manufacturer to another. The original BM46 battery has a capacity of 4100 mAh and a voltage of 3.85V, any significant deviations in performance can cause the charging controller to malfunction.
Tools and workplace preparation required
To make a successful repair, you'll need a minimal set of tools that you can find in any electronics store or order online. Don't try to open your phone with a knife or screwdriver without preparation, this is guaranteed to lead to chips on the frame and scratches on the screen. A quality tool is the key to the preservation of the appearance of your gadget.
Here is a list of what you will need in the process:
- 🔧 Set of screwdrivers (mandatory presence of cross-haired) PH000 and PH00).
- 🎹 Plastic blade or mediator for opening the body.
- 🌡️ A hair dryer or thermophen for warming up glue (optional, but desirable).
- 🧲 Magnetic mat or cog tank.
- 🧤 Antistatic gloves (recommended to protect the fee).
The workplace should be well lit and spacious. Small cogs tend to get lost at the most inopportune times, so use a magnetic mat or spread them out on white paper in order to unscrew. It is also recommended to discharge the old battery to a minimum (until the phone itself turns off) to reduce the risk of short circuits if the shell is accidentally damaged.
Pay special attention to clean hands and surfaces. Fat spots on plumes or contacts can disrupt signal transmission. If you have isopropyl alcohol, prepare it to clean the internal components of dust and glue residue. The cleanliness of the process directly affects the durability of the repair.
The process of disassembling the Xiaomi Redmi 3 body
Disassembly begins with the removal of the back cover, which in this model is removable, but has additional fixing points. SIM-card and memory card to free up the interior space, then gently tuck the lid with a nail or plastic spatula in the area of charging ports or speakers.
Once you remove the plastic lining, you'll see a metal frame that's screwed around the perimeter with lots of screws, and the number of screws can vary depending on the board's revision, so act carefully. All screws are the same size, which makes it easier to do, but requires order when folding.
☑️ Disassembly checklist
When all the screws are twisted, don't pull the frame by force. Walk around the perimeter with a blade, snapping the plastic latches. Inside you'll see the main board, the battery and the camera module. The first thing you need to do is to disconnect the battery plume from the motherboard to turn the device off before you can manipulate it further.
To access the battery itself, you need to remove an additional metal plate covering the bottom of the board and the charging connector, which is usually held on 2-4 screws, and once removed, you will access the bottom plume, which also needs to be gently disconnected using a plastic tool to avoid damaging the contacts.
Removing the old battery and installing a new one
The battery in Redmi 3 is attached to the body with double-sided tape. Over time, the glue loses its properties, but often holds the battery tightly enough. Under no circumstances do not try to tamper with a metal screwdriver - a puncture of the lithium-ion cell shell causes instant ignition.
Use a plastic card or a spatula to gently poke the battery from different sides, gradually separating it from the frame. If the glue holds very strongly, you can slightly warm the back wall with a hairdryer to a temperature of 40-50 degrees, but do not overdo it to avoid melting the plastic elements.
Once the old element is removed, clear the seat of glue residues. The new battery should be equipped with a fresh layer of double-sided tape for secure fixation. Set the battery in a frame, press tightly throughout the area and connect the plume until a characteristic click.
The assembly is done in reverse order. First, the bottom board plume is connected, then the metal plate screen is installed. Make sure all screws are twisted but not pulled so as not to break the thread in the plastic pillars of the case. Make sure that no plumes are clamped with metal parts.
What if the phone doesn’t turn on after assembly?
Calibration and system configuration after replacement
After a physical replacement, the system may not display the charge level correctly, because the power controller "remembers" the parameters of the old battery. To work properly, you need to perform a calibration procedure, which will allow the system to re-determine the real capacity and cut-off points.
The calibration process is as follows:
- 🔋 Completely discharge the phone before automatically shutting down.
- 🔌 Connect the charger and charge up to 100% when off.
- ⏳ Leave your phone on charger for another 1-2 hour 100%.
- 📱 Turn on the device and check the charge level in the system.
You can use special engineering codes or applications for deeper calibration, but in most cases 2-3 full charge-discharge cycles in normal use are enough, which is especially important for MIUI-based devices, where energy saving algorithms are closely integrated with the readings of the battery sensors.
It is also recommended to check the operation of all modules after assembly: the camera, speakers, vibrator and fingerprint sensor (if the model supports). Sometimes, with a careless assembly, thin plumes leading to the auxiliary modules can be damaged.
Table of compatibility and characteristics
When choosing a spare part, it is important to focus on technical parameters. Below is a table that helps to identify original and compatible models of batteries for various versions of the Redmi 3.
| Model phone | Battery code | Capacity (typical) | Tension. |
|---|---|---|---|
| Xiaomi Redmi 3 | BM46 | 4100mAh | 3.85V |
| Xiaomi Redmi 3S / 3X | BN41 | 4100mAh | 3.85V |
| Xiaomi Redmi 3 Pro | BM46 | 4100mAh | 3.85V |
| Compatible analogue | BM46 (High Copy) | 3800-4000 mAh | 3.7-3.8V |
Note that Redmi 3S and 3X models use a different coded battery (BN41), which is physically different from the connector and the pins. Installing the wrong battery is impossible without reworking, so always check the code on the old part before buying.
Security measures and frequently asked questions
Working with lithium-ion batteries requires safety precautions, damage to the cell shell can lead to the release of an electrolyte, which is a caustic substance. If you smell a sharp chemical smell or see smoke, immediately stop working and ensure that the room is aired.
⚠️ Warning: Do not throw your old battery into a regular trash can, take it to a special e-waste disposal facility, as it contains toxic substances.
Many users are wondering whether to update the firmware immediately after replacing the battery. Experts recommend first conduct 2-3 charge-discharge cycles on the current version of the software to stabilize the readings, and only then proceed to update if necessary.
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Keep the packing off the new battery for at least a month, and if you get married, having a box and a check will make it easier to return or exchange goods in the store.
In conclusion, self-replacement of the battery is a cost-effective way to extend the life of your favorite gadget. Provided you use high-quality components and accuracy of execution, Xiaomi Redmi 3 will again please you with a long battery life.
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The quality of replacement batteries is more important than the speed of replacement - a cheap analogue can fail in 2-3 months, nullifying all efforts.