Smartphone Xiaomi Redmi Note 4 for several years is one of the most popular devices of the mid-range segment, but time spares even the most reliable lithium-polymer batteries. If your phone stopped holding the charge, turns off 20-30% or the case is swollen, it's time to think about replacing the battery.
However, the replacement process requires carefulness, as the design of the smartphone involves the use of glue locks and plumes that are easily damaged by inexperienced hands. In this article, we will discuss not only the theoretical aspects of selecting a new battery, but also provide detailed guidance based on real-world experience of disassembling the device. It is critical to use the battery with a 2.0 or higher controller for the Redmi Note 4 (Helio X20), since older versions may not be determined by the system.
Before we take action, we need to prepare the workplace and make sure that all the tools are available. Lack of specialized equipment can damage the display or back cover, which will turn a simple repair into an expensive replacement for entire modules. Next, we will look at each step in detail to minimize risks and ensure a successful outcome.
Diagnostics and selection of a new battery
The first step is to make an accurate diagnosis of the current power supply. It's not always a quick discharge that means physical wear and tear; sometimes the problem is software failures or background processes. You can check the battery's status through the engineering menu by typing the code in your phone ##6485##, where MB_06 The health of the battery, and MF_02 — recharge cycle.
When choosing a new spare part on the market, you can encounter many options, from the original to the original. OEM-The original is usually code-marked. BN41 For a version with a Snapdragon processor, which is the standard for most Redmi Note 4 models. Copies often have less real capacity, indicated on the label, and can fail after several months of active use.
Pay attention to the presence of protective film on the contacts and the quality of soldering of the plume. Cheap analogues often have thin wires and lack of thermal protection, which can lead to overheating of the device.
- 🔋 Capacity: Nominal should be 4100 mAh, typical - about 4000 mAh.
- 🏷️ Marking: Look for the code BN41 on the train, this is a guarantee of compatibility with the payment.
- 🛡️ Protection: Availability of a controller of protection against overdischarge and overheating is mandatory.
⚠️ Warning: Never buy batteries without a protective transport film on the connector, as this may indicate a violation of storage conditions or use.
Tools and workplace preparation required
To make the repair work, you'll need a minimum set of tools, which you can buy from any radio parts store or order online. The main requirement is to have tools for working with small electronics, since the screws in your smartphone are very small and easily lost. Organize the space so that the light falls evenly and the small parts do not roll far.
Special attention should be paid to the tools for opening the case. The back cover of the Xiaomi Redmi Note 4 is planted on a double-sided tape around the perimeter, and a sloppy opening can lead to cracks in glass or plastic. The use of metal blades is not recommended, it is better to prefer plastic or copper.
It is also important to have a heat source on hand to soften the glue. A regular hair dryer may not be able to cope with the task, so it is better to use a temperature-adjusted building hair dryer or a special heating pad.
- 🔧 Screwdrivers: Cross Ph000 and Ph00, flat-footed.
- 🧣 Mediators: Plastic shoulder blades and suction cup for neat opening.
- 🌡️ Heating: A hair dryer or thermal panel for heating the adhesive layer.
- 🧴 Clay: B-7000 or E-8000 fixing.
☑️ Preparation for disassembly
The process of disassembling the smartphone
Start disassembly should only after completely switching off the device and removing the tray. SIM-Heat the perimeter of the back cover during 2-3 minutes to a comfortable temperature for the hand, approximately 60-70 This will soften the glue that holds the lid, and avoid breaking it when you remove it.
Using a suction cup, create a small gap between the lid and the frame at the bottom of the case, gently insert a plastic card or mediator into this gap and guide it along the perimeter, cutting the adhesive layer. Do not immediately remove the lid until you pass along the entire circuit, otherwise you can damage the fingerprint scanner plume that is glued to the inside of the lid.
When you take the lid off, you'll see a metal screen covering the main components, and it's mounted on a few screws that you need to unscrew, and be very careful because there are plumes of the display and touchscreen underneath.
Sequence of action:
1 Warm the perimeter (60-70°C).
2. Disconnect the lower corner with the suction cup.
3. run the mediator around the perimeter.
4. lift the lid without pulling sharply (the risk of a plume).The next step is to disconnect the fingerprint scanner plume from the motherboard, and to do that, gently lift the connector latch and remove the plume, and then you can remove the back cover completely to the side.
Removal of the old battery
The battery in the Redmi Note 4 is attached to double-sided tape and additionally fixed with plastic tongues or screws (depending on the revision of the board).The first thing you need to do is to disconnect the battery plume from the motherboard to turn off the device and avoid short circuit.
Sharp metal objects should not be used to extract the battery, as a puncture of the lithium polymer cell housing will cause it to ignite. It is recommended to use a thin line or plastic card, gently putting on the battery and cutting the adhesive layer underneath.
If the battery is swollen, treat it with extreme care so as not to damage the shell. In case of severe bloating, remove it as quickly as possible and place it in a safe place.
⚠️ Warning: It is strictly forbidden to pierce, bend or heat an old battery above 80 degrees, this can cause a chemical reaction and ignition.