How to get the battery from Xiaomi Redmi 3S: disassembly, tools and precautions

Xiaomi Redmi 3S is one of the most popular budget smartphones of 2016, and is still used by many users. However, over time, the battery capacity inevitably decreases, and it becomes necessary to replace it. Unlike modern models with fixed covers, the Redmi 3S theoretically allows you to get to the battery, but the process requires accuracy and the right tools.

This article will help you understand how to safely remove the battery from the Xiaomi Redmi 3S without damaging the board, plumes or the case itself. We will look at the necessary tools, step-by-step instructions with the photo, as well as common errors that can lead to device failure. If you have never disassembled a smartphone, do not worry: with the right approach, the task is possible even for a beginner.

Preparation for disassembly: tools and conditions

Before you start removing the battery, make sure you have everything you need, the wrong tools are the main cause of damage to the body or internal components.

• 🔧 Plastic blade (or mediator) - for careful liding and disconnection of plumes.
• ⚙️ Cross screwdriver (size) PH00 or PH0) — screw-twisting.
• 🔥 Hair dryer or thermoair station - for softening the glue (optional, but recommended).
• 🧲 Magnetic mat or container – to avoid losing small screws.
• 📱 New battery (if you are planning to replace) – check compatibility with the Redmi model 3S (original. MB11).
• 🧴 Isopropyl alcohol (90%+) — Cleaning contacts and removing glue residues.

Also, make sure that the workplace is well lit, free of dust and moisture, perfect for a flat table, never disassemble your smartphone on a carpet or soft surface, static electricity can damage the board, and if you work in high humidity, use an antistatic bracelet.

Step 1: Turning off and disassembling the body

The first step is to shut down the power completely, and even if the battery is dead, there may be a voltage in the circuit board capacitors, so that you don't short-circuit.

1. Press the power button for 10-15 seconds to make sure the device is turned off.
2. Extract. SIM-card and memory card (if installed).
3. Wait 5-10 minutes – this will help to discharge the residual voltage.

Now we're going to disassemble, and the Redmi 3S has two parts: a front panel with a screen and a back cover, and it's mounted on the latches and glue, so be careful.

• 🔥 Heat the edge of the back cover with a hair dryer (temperature) ~60°C) for 1-2 minutes - this will soften the glue.
• 🕳️ Insert a plastic blade into the gap between the lid and the case (start at the bottom edge where the charging connector is).
• 🔄 Carefully drive the shoulder blade around the perimeter, gradually snapping the lid!

Power's out.|Removed. SIM microSD|Heated edges of the lid|Scapula and screwdriver prepared.-->

Warning: If the lid doesn't lend itself, don't try to pull it off by force. It's probably not softened enough. Reheat with a hairdryer or use more alcohol to dissolve the glue.

Step 2: Disconnecting the plumes and batteries

When you take off the back cover, you'll see the battery covered in black film, but before you take it out, you have to turn off all the plumes that go to the motherboard. Redmi 3S has three.

• 📶 Antenna plume (at the top of the board).
• 🔋 Battery plume (usually red or orange).
• 📱 Display plume (wide, at the bottom).

Use a plastic blade to gently lift the connectors. Never pull the plumes! They are fragile and can break. If the connector fails, check if there is a latch (sometimes you need to lift it with a screwdriver).

Once the plumes are disconnected, you can start removing the battery, and it's glued to the body, so:

1. Carefully tuck the battery with a plastic spatula from any edge.
2. If it does not go away, apply a few drops of isopropyl alcohol under the edge - it will dissolve the glue.
3. Do not use metal tools to prevent battery piercing!

Table: Comparison of battery recovery methods

Step 3: Diagnostic the battery and prepare for replacement

After the battery is removed, check it for bloating, corrosion or damage. If the battery is swelling, it should be disposed of as soon as possible (such batteries are dangerous!).

• 🔍 Appearance: deformation, spots, electrolyte darts.
• 📊 Capacity: the original Redmi battery 3S It has a capacity of 4100 mAh. If the new battery has a smaller capacity, it will last less.
• 🔌 Contacts: Oxidation or pollution can lead to poor compound.

Before installing a new battery, clean the contacts on and inside the board with a cotton swab dipped in isopropyl alcohol. Make sure there is no residue of old glue at the battery attachment site - they can interfere with the tight fit.

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If you notice that the new battery is quickly discharged, check it with a multimeter.The voltage of the serviceable battery should be in the range of 3.7-4.2 V. If the value is below 3.5 V, the battery is defective or discharged.

Common Mistakes and How to Avoid Them

Even experienced users sometimes make mistakes when replacing a battery, and here are the most common ones and ways to prevent them:

• ❌ Using a knife or screwdriver to tamper with the battery → Solution: Use only plastic or wooden tools.
• ❌ Excessive force when removing the cover → cracks in the body or damage to the plumes. Solution: heat the glue and act slowly.
• ❌ Forget to disconnect the battery plume before retrieval → Solution: Always check for a multimeter power outage.
• ❌ Installation of a battery with a smaller capacity → Solution: Buy only original or certified analogues.

Another common problem is poor contact after assembly, and if the smartphone doesn't turn on or the battery doesn't charge, check:

• The density of the battery to the contacts.
• Integrity of the plume of the power supply (sometimes it is damaged during assembly).
• Cleanliness USB-port (dust or oxidation may block charging).

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If the battery is not turned on after the battery is replaced, do not panic. 90% of the time the problem is solved by re-checking the connection of the battery plumes and contacts.

Build a smartphone after replacing the battery

Installing a new battery is only half the battle, and it is equally important to build the Xiaomi Redmi 3S properly to avoid problems in the future.

1. Place the new battery in place, making sure the contacts match the connector on the board.
2. So, make sure you do not put it down (or just put it down!).
3. Connect the battery plume, then the rest of the plumes in reverse order.
4. Set the back cover starting at the top and snap it around the perimeter.
5. So, turn all the stains (not to be worn).

Before the final assembly, test the smartphone:

• 🔌 Connect charging - should appear charging indicator.
• 📱 Turn on the device and check if the battery is recognized (in Settings settings). → Battery).
• 🔋 Run a capacity test with an app like AccuBattery.

If everything is working properly, you can seal the lid, use double-sided tape or a special glue for electronics (for example, the B-7000), apply it in a thin layer, avoiding hitting the speaker or microphone.

FAQ: Frequent questions about battery replacement in Redmi 3S

⚠️ Warning: If you notice that the battery is swelling or deformed during disassembly, don't try to puncture or compress it! Lithium batteries can ignite if damaged. Place it in a sealed container and hand it over for disposal.

⚠️ Warning: After the battery is replaced, the smartphone may show an incorrect percentage of charge in the first 2-3 cycles. This is normal - the controller needs time to calibrate. To speed up the process, completely discharge and charge the battery 2-3 times in a row.