How to replace the battery Xiaomi Mi 9 Lite: the full guide

Smartphone Xiaomi Mi 9 Lite, released in 2019 This year, it is still a popular device because of its AMOLED-But time has a profound effect on the lithium-ion battery, and if your device stops holding charge, it suddenly turns off when you're in the process of shutting down. 20-30% If you're swelling, it's time to think about replacing the battery, and if you're self-repairing, you can save a lot of money and extend the life of the gadget for a few more years.

In this guide, we will take a detailed look at the battery replacement process, focusing on safely disassembling the glass back cover, which is the most fragile element of the structure, and learn what tools will be required to work, how to choose the right new battery, and what to do after installation to calibrate the power system.

Diagnostics and selection of a new battery

Before you start disassembling, you need to make sure that the problem lies in the wear of the battery. Rapid discharge can be caused by background applications or failures in MIUI. Check the energy consumption statistics in the settings menu. If the discharge schedule looks sharp and unnatural, and the phone is warming even in a simple, most likely, the resource of the chemical element is exhausted.

When choosing a new battery for the Xiaomi Mi 9 Lite, it is critical to pay attention to the labeling.The original capacity is 4,030 mAh. There are many analogues on the market, but cheap copies often have a real capacity of half the declared one. Look for models with a BMS protective board that prevents overheating and overcharging.

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Pay attention to the date of production of the battery. Lithium-ion batteries degrade even when stored, so don't buy a cell released more than a year ago.

Original parts often have a hologram and QR-The use of a low-quality analogue can lead to unstable operation of the power controller or, in the worst case, to a fire.

⚠️ Warning: Never use a ballooned battery. Mechanical damage to the battery shell can cause the electrolyte to ignite when punctured. If the battery is too inflated and interferes with the closure of the case, do not press it.

Tools and workplace preparation required

The Xiaomi Mi 9 Lite will require a specific set of tools to repair it properly. Standard home accessories will not be enough, as the design of the smartphone involves using glue to fix components. Prepare a workspace with good lighting and an antistatic mat, if possible.

Here is a list of what you will need to replace successfully:

• 🔥 A hair dryer or thermoplatform for heating the adhesive layer of the back cover.
• 💳 Plastic card or special spatula for opening the case without scratches.
• 🔧 A set of Phillips screwdrivers (cross) size PH00 or PH000.
• 🧲 Magnetic mat or organizer for sorting screws of different sizes.
• 🧴 Clay. B-7000 or E-8000 for sealing the shell after assembly.
• 🧤 Suction cup for neat removal of the back panel.

Space management is key to success. The screws in modern smartphones can vary in length even within the same board. A lost or tangled screw can cause a plume to break or damage the motherboard when assembled.

Safe disassembly process

The most difficult step of replacing the battery with the Xiaomi Mi 9 Lite is to remove the rear glass panel. It is glued around the perimeter, and careless movement can lead to its splitting.

Turn on the dryer at the average temperature and evenly warm the perimeter of the back cover for 2-3 minutes.Do not hold the jet of hot air at one point for too long so as not to damage the display on the back side or internal plastic elements. Periodically check the temperature with your finger - the glass should become hot, but not scalding.

Heating temperature: 80-90°C


Warm-up time: 120-180 seconds




Heating zone: Body perimeter

Once warmed up, place a suction cup at the bottom of the back cover and pull up slightly, creating a small gap. Insert a plastic blade or mediator into the resulting gap, guide the tool along the faces, cutting the adhesive layer. Move slowly, feeling the resistance of the adhesive.

⚠️ Warning: Do not try to cover the lid with metal tools.The metal conducts current and can close the contacts of the battery, and also easily scratches the glass and frame.

Dismantling old components and removing the battery

When you remove the back cover, you will see the interior of the smartphone. In the Xiaomi Mi 9 Lite, the battery is covered with a plastic cover that is attached to several screws and glued to the frame. Carefully unscrew all the visible screws that lock this protection.

The first thing you need to do is to disconnect the battery plume from the motherboard, which is a critical safety step, use a plastic blade to plug the connector up, and only after the power is cut can you touch the other components.

The battery in this model is also fixed with adhesive strips, and you can extract it with a special pulling tongue, if it's preserved, or you can gently tweak it with a plastic card on the bottom, and you can't use excessive force or bend the battery.

When working with the insides of your smartphone, avoid touching the camera plumes and display with your fingers. Skin fat can oxidize over time and disrupt contact. All manipulations are done with confident but easy movements.

Installation of a new power supply and assembly

Before installing a new battery, clean the bed of the residue of old glue. The surface should be flat and clean. If the new battery does not have a sticky base, apply a thin layer of double-sided tape or special adhesive strips that come with the kit.

Connect the new battery plume to the motherboard before you click. Make sure the connector sits flat. After that, you can temporarily turn on the device without gluing the lid to check the system's response to the new battery.

Put the design in reverse order: install plastic protection, twist the screws. Before the final sealing of the case, apply a thin layer of glue B-7000 around the perimeter of the frame. Let the glue dry a little (about 1-2 minutes), then press the back cover and lock the smartphone with rubber bands for 15-20 minutes.

Calibration and primary charging

After the battery is replaced, the system may not display the percentage of charge correctly. In order for the power controller to recalibrate and correctly read the capacity of the new battery, it is recommended to perform a calibration cycle, which will help to avoid a situation where the phone turns off at 15% or charges to 100% in 10 minutes.

Calibration is simple, but it takes time. Discharge the smartphone until it's completely turned off. Then, when it's off, charge it to 100%. Then turn on the phone and, without turning off the charger, wait an hour.

You don't have to make calibration a habit, because deep discharge is bad for lithium-ion batteries, and you just have to do it once after you've replaced it.

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Proper calibration of the battery after replacement is the key to the correct display of charge percentages and stable operation of the energy saving system.

Typical errors and troubleshooting

Even if you follow the instructions, there are some unexpected situations, and one of the common problems is that the phone doesn't turn on after assembly. First of all, check the density of the battery plume connection. Sometimes the connector seems connected, but there's no contact.

If the smartphone turns on but writes "Battery unknown" or doesn't charge, the problem may be in the spare part itself. Cheap copies often don't have a chip compatible with the Xiaomi controller. It's also worth checking the integrity of the plume - if it's not installed sloppy, it's easy to damage it.

If the phone is cyclically restarting, try resetting to factory settings (Settings → About Phone → Resetting). Sometimes the software conflict between the old statistics and the new battery causes the OS to crash.