Disassembly of the external battery Xiaomi: instructions with photos and warnings

Xiaomi's external batteries are some of the most popular on the market for their price, capacity and reliability. However, even the best power bank fails over time: they stop holding the charge, inflate or refuse to turn on. Most of the time, the cause is degradation of lithium-ion cells, but sometimes the problem lies in the electronics — charge controller, fuses or connectors. To disassemble the Xiaomi case is not as easy as it seems: the manufacturer uses gluing, latches and even soldering on some models to prevent self-repairing.

This article will help you safely open the external battery without damaging the internal components. We will look at tools that actually work (and which are useless), show unique techniques for models with adhesive joint, and explain how to recognize a bloated battery and what to do if the body is already deformed. Importantly, disassembling lithium batteries always carries risks, from short circuit to fire. If you are not sure of your skills, you should contact a service center.

Preparation: security tools and measures

Before you start disassembling, make sure you have everything you need. The minimum set of tools includes:

• 🔧 Plastic mediators (or guitar mediators) – to disconnect latches without scratches.
• 🔨 Thin screwdriver with a flat sting (1-2 mm) - for smearing adhesive seams.
• 🧴 Isopropyl alcohol (90%+) — dissolves glue and cleanses contacts.
• 🔥 Refractory substrate (ceramic tiles, metal sheet) - in case of fire.
• 🧤 Nitrile gloves – protection against chemical burns in contact with electrolyte.

What's not good for disassembly:

• ❌ Knives and metal blades – cut through the body or damage the battery.
• ❌ Hair dryer or heater over 60°C – risk of electrolyte swelling or leakage.
• ❌ Hammer and chisel - even if "so fast" it's guaranteed to destroy the fee.

⚠️ Note: If the battery case is already swelling or deformed, do not try to disassemble it at home. Lithium-ion cells in this state are extremely unstable - the slightest damage to the shell can lead to thermal acceleration (uncontrolled heating to 800).°In this case, the only safe option is to dispose of the device at a special reception point.

Before starting work, completely discharge the battery (up to 0%), which will reduce the risk of short circuits, and prepare a sealed container (for example, a jar with a lid) - you will need to fold the removed elements, unless you plan to replace them immediately.

Step 1: Determination of the type of housing and method of attachment

Xiaomi uses three main types of enclosures for external batteries:

1. Glue (e.g. Mi Power Bank 3 10000 mAh) – the upper and lower parts are glued around the perimeter.
2. Latches + Adhesives (e.g. Redmi Power Bank 20,000 mAh) – latches on the sides + point-glue.
3. Screw (rarely, for example, some versions of Mi Power Bank Pro) - the case is mounted on 2-4 screws under rubber legs.

To see what you have, check the box:

• 🔍 If you see rubber legs, try to gently tamper with them: screws may hide under them.
• 🔍 If the case is smooth, without visible seams - this is a glue option.
• 🔍 If you can hear a light click when you press the side faces, there are latches.

For screw models, it's simple: unscrew them and gently unplug the body. But the glue and latch options require caution. Start by heating the glue (but not above 60).°C!: You can use a dryer at minimum power or put the battery on a warm battery for 5-10 minutes.

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If you have a latch model, try gently putting a plastic mediator in the seam and swiping it around the perimeter, listening to the clicks, and often the case opens without heating.

Step 2: Disconnecting the body - step-by-step instructions

Consider a universal algorithm for adhesive models (for example, Mi Power Bank 3 10000 mAh):

1. Apply isopropyl alcohol around the perimeter of the seam with a cotton swab. Wait 2-3 minutes - the alcohol partially dissolves the glue.

2. insert the plastic mediator into the widest seam (usually around USB-port) and carefully guide it along the hull, slowly expanding the gap.

3 If the housing fails, repeat the heat (no longer than 15 seconds per seat!) and try the mediator again. Don't apply force - it is better to act slowly.

4 As soon as you have a gap of 1-2 mm, insert a second card (or another mediator) into it and continue moving on. The goal is to evenly separate the body around the perimeter.

For latched models (e.g. Redmi 20,000 mAh):

1. Start with. USB-The port is the weakest part. Put the mediator in and pull up.

2. Swipe the mediator along the long side, pressing the latches. You will hear the characteristic clicks.

3.If the body does not open, check if there are hidden screws under the stickers or legs.

⚠️ Warning: If you have a strong chemical smell when you're unclose, or if you see a white plaque on your hands, it's a sign of electrolyte leakage. Stop working immediately, wash your hands with soap and water, and ventilate the room!

Step 3: Extracting and Diagnosing Internal Components

After a successful autopsy, you will see:

• 🔋 Lithium-ion cells (1-2 pieces, depending on the capacity).
• 📱 Charge controller board (usually soldered to batteries).
• 🔌 USB-Ports (may be soldered or on connectors).
• 🛡️ Thermocouple or fuse (in models with overheating protection).

The first thing to do is to check the batteries:

• ✅ Normal condition: flat surface, no bloating, contacts clean.
• ⚠️ Suspicious condition: slight bulge (up to 1 mm), white plaque on contacts.
• ❌ Critical condition: severe bloating, cracks, smell of burns.

If the batteries are swollen, don't touch them with your bare hands, use gloves. Carefully unplug the controller board (usually mounted on double-sided scotch or soldering) and remove the elements. You can use a multimeter to check the voltage:

• 🔋 3.7–4.2V — norm.
• 🔋 2.5–3.5V — deep discharge, low-current charging is required.
• 🔋 0–2.4V — element is dead, it cannot be restored.

And you can see the controller board, and it's often caused by burnt resistors or oxidized contacts, and if you see blackened parts or green plaque, you'll have to replace the board.

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If the battery doesn't turn on, but the batteries are normal, 90 percent of the time the charge controller is to blame, and it can be replaced or repaired (if soldering equipment is available).

Step 4: Replace batteries or repair boards

If you've diagnosed a defective element, you need to replace it.

1. Order new batteries of the same capacity and size (e.g., Mi Power Bank 3 10000 mAh will fit the elements). LG INR18650 MJ1 3500mAh).
2. Solder off old batteries from the board using a soldering iron with solder suction.
3. Seal new elements while respecting polarity (+ ce +, – ce –).
4. Secure the batteries on double-sided scotch or heat-glue.

For the repair of the controller board:

• 🔍 Inspect for burnt components (blackened resistors, swollen capacitors).
• 🔧 Replace damaged parts if you have experience soldering SMD-component.
• 🧹 Clean the contacts with alcohol from oxidation.
• 🔌 Check the chain with a multimeter in vertebrae mode.

⚠️ Warning: When soldering batteries, never overheat them - the maximum contact temperature with the soldering iron stinger should not exceed 3-5 seconds. Use low-temperature solder (with a melting point of up to 200)°C) and water-based flux.

If you are not sure about your soldering skills, it is better to buy a ready-made controller board for your model (they are sold on AliExpress or in specialty stores).

Step 5: Assembly of the body and check of performance

After replacement of components:

1. Make sure all contacts are isolated (use a heat-shrink tube or tape).
2. Check the polarity of the battery connection – an error will result in a short circuit.
3. Carefully put the fee and batteries inside the case.
4. Lubricate the edges of the body with a thin layer of silicone sealant (not glue!) for better sealing.
5. Squeeze the halves of the case and fix them with paint tape for 12-24 hours.

To check the availability:

1. Connect the battery to charge for 30 minutes.
2. Check the voltage at the exit with a multimeter (should be) 5V ± 0.2V).
3. Connect the load (for example, a smartphone) and make sure that the charge is coming.

If the battery is not started:

• 🔋 Check if the safety lock on the board has worked (sometimes it needs to be closed).
• 🔌 Make sure that USB-jack-up.
• 📱 Try to reset the controller by briefly closing the contacts B+ B!).

Frequent Mistakes and How to Avoid Them

Even experienced masters sometimes make mistakes when disassembling a power bank.

• 🔥 Battery overheating when soldering → use heat sink (for example, a crocodile clamping»).
• 💥 Closing contacts with metal tools → Only work with plastic mediators.
• 🔋 Using batteries of different capacity → The elements must be identical in parameters.
• 🧴 Excess glue during assembly → thin-skinned.
• ⚡ Checking unloaded performance → Always test with a connected device.

If the battery does not hold a charge after assembly, possible reasons:

• 🔋 Batteries are not calibrated – fully discharge and charge 2-3 times.
• 📱 The controller does not recognize new elements – firmware may be required (for some models).
• 🔌 Poor contact between batteries and board - check ration.

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If the battery is warmer than usual after repair, turn it off immediately, which is a sign of a malfunction of the controller or a short circuit in the circuit.

FAQ: Answers to Frequent Questions