Xiaomi Redmi Note 3 Pro (also known as Kenzo) has been a budget legend for more than a decade, but time is not spared even the most reliable devices. The main victim of time is a lithium-ion battery that eventually loses its capacity, begins to quickly discharge or suddenly turn off in the cold. If your phone stopped holding a charge at least half a day, and the percentage of charge jumps from 40% to 10%, it’s time to think about replacing the battery on this model – a task that is quite feasible for a person with minimal skill and care.
Unlike many modern monolithic designs, the Redmi Note 3 Pro has a removable back cover, which makes it much easier to access the insides, but the battery design is not the easiest. The main difficulty is that the battery is glued to the body and the train runs under the motherboard, which requires partial disassembly of the device. It is critical to turn off the battery plume before any work with the motherboard to avoid short circuit. In this article, we will discuss in detail the process of selecting a new battery, preparing tools and step-by-step replacement, so that your smartphone will enjoy autonomy again.
Before you start disassembling, you need to make sure that the problem lies in the physical wear of the battery, not in the software failure or malfunction of the charge controller. Often users rush to change the hardware, when you just reset the usage statistics or reflash the device. However, if the phone is already 5-7 years old, the degradation of the chemistry inside the cell is a natural process, and the software methods here are already powerless. Below we will consider all the steps from diagnosis to the final calibration so that you can perform the repair efficiently and safely for your gadget.
Diagnostics and selection of a new battery
The first step is to accurately diagnose the current state of the battery. Android and MIUI do not have a built-in detailed battery health analyzer that shows the real residual capacity in milliamp hours (mAh). To get reliable data, the best way to use third-party utilities like AccuBattery or AIDA64. Install the application, fully charge the phone to 100% and let it work in normal mode at least one full discharge cycle, which will allow the program to calculate the real capacity and compare it with the factory.
If the diagnosis shows wear and tear of more than 30-40% or the presence of errors in the operation of the controller, you should start looking for a new battery. The original batteries for the Redmi Note 3 Pro are labeled BM32 and a capacity of 4000 mAh. There are many options on the market: from cheap copies to quality analogues and rare originals. It is important to understand that the “original” in the Xiaomi packaging is extremely difficult to find today, most often under this name sold refurbished elements or quality OEM-China.
When choosing a new battery, pay attention to the following criteria:
- 🔋 Capacity: The claimed capacity must be 4000 mAh (sometimes there are reinforced versions at 4100 mAh, but the difference is minimal).
- 🏷️ Marking: The stamp must be marked BM32, Otherwise, the battery may not be determined by the system.
- 📏 Dimensions: The thickness of the new battery should not exceed the thickness of the original, otherwise the back cover may not close or swell.
- 🔌 Connector: The connector must match the exact location of the contacts, as the Kenzo uses a specific connector.
⚠️ Warning: When buying a battery, be sure to check its voltage with a multimeter before installing. If the voltage is below 3.0 V, the battery must be "waked up" with a special charger for the Li-Ion, otherwise the phone may not see it.
Tools and workplace preparation required
Quality repairs are impossible without the right tool. To replace the battery with the Xiaomi Redmi Note 3 Pro, you will need a minimum set that can be assembled at home or bought at any radio parts store. Don't try to replace the battery using only a knife and tape - this will damage the case and plumes. Workplace preparation also plays an important role: choose a well-lit table with a hard surface and remove all metal objects to avoid accidental closure of contacts.
The list of necessary tools includes:
- 🛠️ Set of screwdrivers: mandatory presence of a cross screwdriver PH000 or PH00 screw-hole.
- 🎴 Plastic blades (openers): necessary for careful removal of the back cover and snapping plumes without damaging the plastic.
- 🌬️ Hair dryer or thermophen: necessary to heat the glue that holds the battery. Household hair dryer is also suitable, but you will need to heat longer.
- 🧲 Magnetic mat or container: for sorting screws, as the phone uses screws of different lengths.
- 🧤 Antistatic gloves: desirable to protect electronics from static electricity, especially in dry rooms.
Also pre-arrange the B-7000 or E-8000 glue to fix the new battery and back cover. Regular superglue cannot be used categorically - its pairs can settle on the cameras and speakers, spoiling them, and the glue itself becomes too brittle or, conversely, too fluid when heated. Make sure you have tweezers on hand to extract small parts and possibly a suction cup for convenient removal of the lid.
☑️ Ready for repair
The process of disassembling the smartphone
So the most important thing to do is to disassemble the device. The Redmi Note 3 Pro is designed to hold the back of the latch on the perimeter and one screw under the plug. SIM-So you don't want to damage your cards and memory cards if you open them in a sloppy way, and then you flip the phone over and find a round plug at the bottom of the back cover (near the charging socket) that hides a screw that you need to unscrew.
Once the screw is removed, take a plastic spatula or a special suction cup. If you use a suction cup, attach it to the bottom of the lid, pull it up slightly to create a gap, and insert the spatula. Drive the spatula along the perimeter of the case, carefully snapping plastic clips. Don't use excessive force: if the lid doesn't go, you missed the screw or didn't crack the previous section well enough. Move around until the lid is completely free.
When you take the lid off, you'll see a metal frame covering the mainboard and the battery, which is screwed with a lot of screws around the perimeter and in the center, and you'll unscrew all the visible screws, paying attention to their length, because the longer ones usually go along the edges, and when you remove the frame, you'll have access to the motherboard. First action: gently disconnect the battery plume from the socket on the board, and you need to do this with a plastic blade or a nail, putting the connector up, but not pulling the wires.
Then you unscrew the metal plate covering the bottom of the board and the charging connector to access the battery plume. The battery plume on the Redmi Note 3 Pro runs under the motherboard, so you can't just pull it out without taking the board off. Carefully disconnect all the plumes (cameras, display, buttons) by remembering their location, and remove the motherboard.
Nuances of motherboard screws
Removing the old battery and installing a new one
The old battery in Xiaomi Redmi Note 3 Pro is attached to double-sided tape, which eventually loses its properties or, conversely, "fits" to the body. Under no circumstances try to pull the battery by force, piercing it or erasing the body - this can lead to lithium fire. For safe extraction, you need to warm up the back of the case, where the battery is located. Use a hair dryer, warming the battery area for 2-3 minutes to a temperature of about 60-70 degrees (the hand should be hot, but tolerant).
Once warmed up, take a plastic card or a spatula and gently tuck the edge of the battery. If possible, use a special hood with a suction cup. Slowly and smoothly separate the battery from the body, helping yourself with a spatula. If you feel strong resistance, warm up the case again. After removing the old battery, clean the seat of the residue of old glue and tape. The surface should be clean and low-fat for reliable fixation of the new element.
Installation of the new battery is carried out in reverse order:
- Apply a thin layer of B-7000 glue to the body or the battery itself (avoid getting glue into connectors and contacts).
⚠️ Warning: Don't turn on your phone immediately after you install a new battery. 15-20 You can leave the device alone for an hour, and you can switch on the device early, and you can shift the contacts.
Assembly of the device and check of performance
Once the new battery is installed and the glue is dry, we begin to assemble. Put the motherboard in place, carefully straighten all the plumes so that they are not twisted or clamped. Connect all the connectors to a characteristic click, which is a guarantee of good contact. Pay special attention to the main plume of the display and the battery plume. Install the metal clipplates and twist all the screws, observing their order and length.
Before you install the back cover, you should do a primary test. Connect the battery plume and press the power button. If the screen catches fire and the phone starts to load, you're halfway there. Check if the charging is determined, if the touchscreen is working and the sound is working properly. If everything is working, turn off the phone and install the back cover, snapping all the clips around the perimeter and twisting the final screw from the bottom.
Once fully assembled, turn on your smartphone and wait for the system to boot. The first few charge-discharge cycles may not be right: the phone may be showing 100% and shutting down abruptly or hanging for a long time at 1%. This is normal for a new battery, since the power controller needs time to calibrate. Full calibration usually takes 3-5 full cycles.
💡
Successful replacement is confirmed by stable stress under load and the absence of sharp jumps in the percentage of charge in the first days of use.
Calibration and features of operation
After replacing the battery with the Xiaomi Redmi Note 3 Pro, it is strongly recommended that calibration be performed, which will help the system correctly display the charge level and prolong the life of the new battery. Calibration consists of fully discharging the device before turning off, followed by charging to 100% when off, a process that allows the controller to remember the real capacity of the new cell.
For proper calibration, follow the following steps:
- 🔄 Cycling: Repeat the procedure 2-3 time for the best result.
The table below shows the main parameters that should be monitored after replacement:
| Parameter | Normal value. | Anxious symptom |
|---|---|---|
| Tension at rest | 3.7. to 4.2 B | Below 3.5 B or higher than 4.3 B |
| Current consumption (simple) | 10 - 30 m | More than 50 mA without running applications |
| Temperature during charging | 35 - 45 °C | Above 50°C |
| Opening time (screen) | 4 - 6 hours | Less than 2 hours of active screen |
Remember that the new battery requires careful handling in the first weeks. Try not to let the device run deep into zero and not overheat. Following these simple rules will significantly extend the life of the updated Redmi Note 3 Pro and enjoy its work for a long time.
💡
To check the quality of soldering of the contacts of the battery after replacement, slightly press your finger on the socket area when the phone is turned on. If the screen blinks or the phone reboots - the contact is bad, you need to go over.