Xiaomi Redmi Note 8, released in 2019, has earned a reputation as one of the most reliable mid-range devices. However, the lithium polymer battery has a limited life of recharge cycles, and after 2-3 years of active use, the capacity begins to fall rapidly. If your device stops holding charge, spontaneously turns off at 20-30% or is very hot, then it is probably time to replace the power source.
Replacing the battery on your own is a cost-effective solution that allows you to extend the life of your gadget for another couple of years without buying a new device. It requires care, but it is not very difficult for someone with basic skills in technology. The main thing is to understand that you open the case, and any action you take at your own risk.
In this article, we will discuss the entire process in detail, from the preparation of the workplace and tools to the final calibration of the new battery. We will pay special attention to the nuances of disassembly of the Redmi Note 8 model, since the design of this smartphone has its own characteristics that distinguish it from older or newer models of the line.
Preparation of the workplace and necessary tools
Before you start disassembling, you need to have a comfortable and safe workspace, you need a table with good lighting, where nothing gets in the way, and the small details are not lost, and the ideal option is to have an antistatic mat, but at home, a clean, dry surface is enough.
To do this successfully, you'll need a set of specialized tools, which can take a long time without them, and the risk of damaging fragile plumes or breaking the rear window will increase significantly. Don't try to replace the battery with just a knife or a kitchen set screwdriver.
- 🔧 Precision screwdrivers (Cross Phillips #00 and #0, flat).
- 🎴 Plastic mediators (scapula) for opening the body.
- 🌡️ Hair dryer or heater plate for softening glue.
- 🧷 dielectric-coated tweezers.
- 🧴 Isopropyl alcohol and sucker.
Special attention should be paid to heating elements. The hair dryer should have temperature adjustment so as not to overheat the display matrix or plastic elements of the case. If the hair dryer is not available, you can use a sealed hot water bag, but this is less efficient. Also prepare the screw containers so that they do not confuse them when Assembly.
Safety measures and diagnostics of battery condition
Working with lithium polymer batteries requires strict safety precautions. Damage to the battery casing can lead to fire or chemical burn. If you notice that an old battery is swelling, act with the utmost care: do not press it with sharp objects.
⚠️ Attention: If the battery is overblown and occupies more than 10% of the body volume, it must be removed very carefully!
Before you start physical work, you should do a software diagnostic, and there's a hidden engineering menu in the MIUI shell that allows you to evaluate wear, and type ##6484## into the dialer to get into the CIT menu, and you can find a battery test and see its current state.
It is also important to completely discharge the device before disassembly, which will reduce the risk of short circuits if the plumes or contacts are accidentally damaged. The optimal charge level for starting work is 5-10%, but it is better to wait for the smartphone to spontaneously turn off.
The process of disassembling the case Xiaomi Redmi Note 8
The Redmi Note 8 has a glass back cover that is attached to a two-part glue, which makes the opening process more delicate than plastic counterparts. The first step is always to remove the tray. SIM-This is critical because the screws are often hidden under the tray or in the immediate vicinity.
Once the tray is removed, warm the perimeter of the back cover. Use a hair dryer, evenly warming the edges for 2-3 minutes. The temperature should not be too high to damage the display on the back. You can check readiness by carefully trying to separate the edge with a mediator.
- 🔥 Warm up the edges of the body with a hair dryer to a comfortable temperature for the fingers.
- 💳 Remove the tray. SIM-Maps and put them in a safe place.
- 🔪 Carefully enter the mediator into the gap between the frame and glass.
- ✂️ Swipe with a mediator or a special string around the perimeter, cutting the glue.
When the glue is softened, use a suction cup to lift the back cover slightly, and insert a plastic spatula. Move slowly without making sharp jerks. Inside, near the top edge, there is a plume of a fingerprint scanner (if you have one in your modification) or just a space where you need to be careful.
When you remove the back cover, you'll see the internal layout. 8 The battery module is covered with an additional plastic panel that is screwed up, and you'll need a cross screwdriver to unscrew all the visible screws, and the number of screws can vary depending on the regional version, but they're usually around. 10-12 piece.
Removing the old battery and turning off the plumes
Once the plastic panel is removed, the main components are accessed, and the first thing you need to do is to disconnect the battery plume from the motherboard, which is a must before any other manipulations inside the smartphone to prevent short circuits.
The battery plume in the Redmi Note 8 is plugged into the bottom of the board, often under a decorative bar or next to the charging connector. Use a plastic shoulder blade or nail (if available) to gently fit the connector up. Don't pull the wires!
☑️ Checklist before removing the battery
The battery in this model is also planted on glue, but not as aggressively as the back cover. It is convenient to use special sticky tongues to remove it, if they are provided by the design, or gently tweak the battery with a plastic card from the bottom. Metal tools are prohibited - high risk of puncture.
If the battery is sitting tight, you can slightly warm the area underneath it through the screen (very carefully) or through the open space with a hairdryer. The main thing is not to bend the battery. Lithium polymer cells are sensitive to deformation, and even a slight bending can disrupt the internal structure of the cells.
After you remove the old cell, compare it to the new one. Labeling, voltage and connector should be exactly the same. Usually, this model uses a 4,000 mAh battery. Make sure the new battery has a protective film on the contacts.
Installation of a new battery and assembly of the device
Before installing a new power source, you need to thoroughly clean the bed of the residue of old glue. Use isopropyl alcohol and a plastic shoulder blade. The surface should be smooth so that the new battery fits tightly and does not hang around inside the case.
Apply a special B-7000 glue to the new battery or use double-sided electronics tape. Do not use superglue (cyanacrylate), as it becomes brittle when heated and can damage the battery the next time you replace it.
| Assembly stage | Action. | Important nuance |
|---|---|---|
| 1. Preparation | Cleaning the frame of the glue | Use alcohol 99% |
| 2. Fixation | Applying glue to the battery | Don't make contact. |
| 3. Connection | Installation of the plume | Before the connector clicks |
| 4. Test. | Incorporation before full assembly | Screen reaction check |
Set the battery back in place, press it for a few seconds to grab the glue. Then plug the plume into the motherboard. Make sure the connector is flat and locked. Now you can temporarily close the case (without screws) and try to turn the device on by pressing the power button.
If the smartphone is on and shows the correct percentage of charge, you can proceed to the final assembly. Place all the screws of the plastic panel in place, following the order (usually twisted diagonally), then apply the new glue to the frame of the case and press the rear glass cover.
What if the phone doesn’t turn on after replacement?
Calibration and first start of the new battery
After successful replacement and assembly, it is important to correctly conduct the first charge cycle, which will help the power controller correctly determine the real capacity of the new battery and display the correct percentage of charge, skipping this stage can cause the phone to turn off at 15-20%.
Put your smartphone on charge when it's off. Use the original charger or certified Quick Charge-enabled analog. Charge until the indicator reports 100% charge.
- 🔋 Charge the device to 100% when switched off.
- 📱 Turn on your phone without turning off the charger.
- ⏳ Wait until the system is 100 again%.
- 🔌 Turn off charging and use your phone as normal until full discharge.
Full discharge in this case means when the phone turns off. Then put it on charge again (you can turn it off) and charge up to 100%. This discharge-charge cycle should be repeated 2-3 times, this levels the readings of the controller.
⚠️ Warning: Don't use the Play Market calibration apps. They often require root rights and can do more harm than good. The best calibration is the natural cycles of the power controller. MIUI. 💡To extend the life of the new battery, try not to allow the charge to fall below. 15-20% Do not keep your phone on charge continuously after reaching 100%. The optimal range for lithium polymer batteries is from 20% before 80%. Even with a careful build, there can be unforeseen situations. One of the common problems is the message that the battery is not certified or a charging error. In the case of Xiaomi, it can be a software glitch or a bad contact. If the phone shows a charging error, try restarting the device.If the problem persists, it may be that the connector has clogged up with dust or oxidized. Carefully wipe the contacts with alcohol, it is also worth checking if the plume is squeezed when assembling the case, another common problem is a quick discharge immediately after replacement, which may indicate that the battery has been in storage for a long time and is deeply discharged, or it is defective. Let the device work quietly for a couple of days, and if things don't change, you may need to replace the item under the seller's warranty. 💡A high-quality battery and a neat build are key to a long-lasting smartphone. Saving on components often leads to re-repair after a few months. In conclusion, it is worth noting that replacing the battery with the Xiaomi Redmi Note 8 is a very real task for a home craftsman. Compliance with technology, using the right tools and attention to detail will allow you to restore the autonomy of the device. However, if you are not sure of your abilities, it is better to contact the service center so as not to lose the warranty or damage other nodes of the smartphone. Can you use a battery with a larger capacity than the original? Theoretically, if the dimensions and connector are the same. But the power controller may not work properly with non-standard capacity, and the increased dimensions can damage the screen or the back cover. How long does it take to replace the battery at home? 30-40 The new guy should lay around. 1-1.5 You have to take a few hours to take your time and do all the steps carefully, especially the glue, do you have to reset your phone after you change it? You don't have to reset it, and the system will rewrite the battery statistics. However, the calibration cycle (full discharge and charge) is necessary to correctly display the percentages. Which glue is best used to fix the back cover? The best choice is the B-7000 or E-8000 glue. These remain elastic after drying, making it easier to reopen, and seal the joints well.