How to disassemble a portable Xiaomi battery: detailed instructions with photos and tips

Why you might need to break up Xiaomi Power Bank

Xiaomi's portable batteries are known for their reliability, but even they fail over time. The most common problems are battery bloating, capacity loss after a battery breaks down. 2-3 years of use or mechanical damage to the housing Disassembly may be required to replace the battery cells, repair the control board or clean the contacts from oxidation.

It is important to understand that disassembling Xiaomi power bank automatically voids the warranty if it is still valid. The manufacturer does not provide for repairs - most models are sealed and some even have laser engraving at the seam, but with the right approach, you can disassemble the device without critical damage.

In this article, we will look at:

• 🔧 What tools will be needed for a careful disassembly
• 📱 Step-by-step instructions with nuances for different models (Mi Power Bank 3, Redmi) 10000mAh, Xiaomi 20000mAh)
• ⚠️ Typical errors that lead to a board break or short circuit
• 🔄 How to assemble the device back with minimal traces of intervention

Preparation: security tools and measures

Before starting the disassembly, make sure you have everything you need, and without the right tools, you're at high risk of damaging the body or the internal components.

• 🔪 Plastic mediator (or guitar mediator) – to separate the glued parts of the body
• 🔧 Cross screwdriver (usually) PH00 or PH0) — screw-like
• 🧲 Magnetic screwdriver or tweezers - so as not to lose small screws
• 🔥 Construction hair dryer (power) 1500-2000 W) - for softening the glue
• 🧴 Isopropyl alcohol (90%+) — Cleaning contacts and removing glue residues
• 🛡️ Dielectric gloves - protection against possible breakdown of voltage

If you are planning to replace the battery cells, additionally prepare:

• 🔋 New lithium-ion cells (e.g., 18650 or 21700 with parameters identical to the original)
• 🔌 Spotter or soldering iron with a thin sting (power) 30-60 Watt)
• 🧵 Thermal tube or tape for insulation of contacts

⚠️ Warning: Never disassemble a bloated battery in an enclosed area! Lithium-ion cells can ignite or explode if damaged. Work outdoors or in well-ventilated spaces with a Class D (metal) fire extinguisher or sand on hand.

Step-by-step instructions: how to disassemble the body

The process of disassembly depends on the model, but the general scheme is the same for most power bank Xiaomi (20000mAh).

Step 1: Heating the case to soften the glue

Xiaomi's body is glued around the perimeter with heat glue. To separate the halves, you need to heat the seam to the surface. 60-80°C. Use a building hair dryer:

1. Set the temperature on 150-200°C (not higher!).
2. Keep the hair dryer at a distance. 5-7 cm from the body, evenly warming the seam in a circle.
3. Heat each side on 20-30 seconds.

Don't overheat the plastic, it can deform. If you don't have a hair dryer, you can use hot water (plug the case onto the top). 1-2 minute-in-water 60-70°C), but this method is risky for electronics.

Step 2: Separation of halves of the body

After heating, insert a plastic mediator into the seam between the halves of the case. Start at the corner where it is located. USB-The port is usually thinner, and you need to carefully drive the mediator along the seam, gradually increasing the gap.

If the hull fails:

• 🔥 Reheat again.
• 🔪 Try another angle - sometimes the glue is applied unevenly.
• ⚠️ Do not use metal tools (knives, screwdrivers) – they leave scratches and can close contacts!

Step 3: Removing the board and batteries

After the separation of the body, you will see:

• 🔋 Battery cells (usually 18650 or 21700) connected in parallel.
• 📱 Control board with charge/discharge controller (usually labeling begins with BQ, TP or SY).
• 🔌 Connectors for USB-port and indicator.

To extract the fee:

1. Disconnect the plumes (greatly pull the black tongue of the connector).
2. If the board is glued, heat it with a hair dryer on the back side.
3. Turn away the screws (if any) and charge off the board without touching the contacts with your bare hands.

⚠️ Warning: Charged capacitors may remain on the board even after shutdown! Tweezers B contacts before work+ and B- (minus and plus batteries) via resistor 100 Ohm on 5-10 seconds to discharge the residual voltage.

Features of disassembling popular Xiaomi models

Not all Xiaomi power bank is understood in the same way, and the table below shows the key differences for the popular models:

For models with aluminum body (20000mAh and 30000mAh) It may require milling of the seam along the perimeter, which is a risky method, because if you work sloppy, you can damage the internal components. Alternatively, use a special glue solvent (for example, Loctite 7649), but it can damage plastic parts.

If you are familiar with Xiaomi Mi Power Bank 3 Pro, please note:

• 🔋 Double battery insulation – it cannot be damaged.
• 📱 Additional protection chip on the board (marking) DW01A).
• ⚠️ Thin plumes - they are easy to break with careless extraction.

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If the sleeves are in the sleeve, then put them on the sleeve. WD-40 Or isopropyl alcohol and wait. 5-10 Then try to unscrew again, pressing the screwdriver with force.

Replacement of battery cells: what you need to know

If the cause of the disassembly is a loss of capacity or a bloating battery, you'll need to replace the cells.

Selection of new batteries

Use only high-quality items from proven brands:

• 🔋 Samsung INR18650-35E (3500mAh, 10A)
• 🔋 LG INR18650-HG2 (3000mAh, 20A)
• 🔋 Sony VTC6 (3000mAh, 30A)
• 🔋 Molicel P26A (2600mAh, 35A)

For Xiaomi models 20000mAh and 30000mAh The elements 21700 may be used (e.g., Samsung). 50E or Molicel P42A). Never mix cells of different types or containers – this will lead to imbalance and quick failure.

Selling new elements

When replacing batteries, follow the rules:

1. First, discharge the old cells to 0 V (close the contacts through the resistor).
2. Solder off old elements without overheating the board (use a soldering iron with a power of no more than 60 watts).
3. Seal new cells while observing polarity (+ ce +, − ce −).
4. Insulate the contacts with a shrink tube or a capton.

After the replacement, be sure to check:

• 🔋 Voltage on new cells (should be 3.6-3.7 V on each cell).
• 🔌 Resistance between B+ and B- (should be close to 0 ohms).
• 📱 The operation of charge indicators (if not all are burning - the problem is in the board).

⚠️ Note: If power bank does not turn on after battery replacement, check: Cell connection polarity (confused) +/− Integrity of the fuse on the board (can burn when shorted) Availability of a balancing resistor (for multi-ban assemblies).

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When replacing batteries in Xiaomi power bank, use elements with similar discharge current parameters. 10A, The new ones must also support such current, otherwise the device will shut down at high load.

Building: How to minimize traces of interference

After the repair, you need to assemble the power bank so that it looks as original as possible.

Cleaning and preparation of parts

Before assembly:

1. Remove the remnants of the old glue from the case with isopropyl alcohol.
2. Check the integrity of the sealing rubber (if any).
3. Apply a thin layer of silicone lubricant to the screw thread (prevent corrosion).

Sticking together

For sealing, use:

• 🧴 Double-sided scotch 3M VHB (thickness 0.5-1 mm) - reliable and accurate.
• 🔥 Thermoclee (applied with a gun) – cheaper, but less durable.
• 🧪 Epoxy adhesive (e.g. Loctite Hysol) for maximum strength.

When bonding:

1. Apply the glue in a thin layer around the perimeter of the lower half of the body.
2. Set the board and batteries, connect all the plumes.
3. Carefully combine the halves of the body and fix with rods for 12-24 hours.

If the body was damaged during disassembly, you can mask the defects:

• 🖌️ Acrylic paint (select the color by code) RAL 9003 for white models).
• 🔥 Polishing (for aluminum cases, use paste) GOI).
• 🏷️ Stickers (for example, a thermo application with the Xiaomi logo).

Common Mistakes and How to Avoid Them

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

• ⚡ Short circuit - occurs when touched with tweezers or screwdriver + and − Always use dielectric tools!
• 🔥 Battery overheating - soldering without heat sink can damage the cells. Use a radiator or cooler clamps.
• 🧲 Loss of screws – power bank Xiaomi often uses propellers of non-standard sizes.Photograph their location before disassembly.
• 📉 Cell imbalance: Replace only one battery in a multi-bahn assembly!
• 🔌 Damage to plumes - especially relevant for models with USB-C And Quick Charge. Unplug the connectors by pulling the black tongue, not the wires!

If the device does not work after assembly:

1. Check the fuse on the board (can burn with KZ).
2. Measure voltage to B.+ and B- (should be 3.7-4.2 V for one cell).
3. Check the integrity of the thermistor (responsible for overheating protection).

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If the power bank doesn't charge after the battery is replaced, check the contacts of the thermistor (a small black sensor on the cell), it can come off when soldered carelessly, without it, the board blocks charging.

When the Disassembly is Inappropriate: Alternative Solutions

Sometimes, Xiaomi’s power bank repairs cost more than buying a new one.

• 💸 The cost of new batteries exceeds 60% of the price of the new power bank.
• 🔧 The control fee burned (replacement will cost 1000-1500) ₽ + job).
• 🔋 The body is severely deformed (for example, after falling from a height).
• ⚡ Device over 5 years old – modern models are more efficient.

Instead of repairs, you can:

1. Buy a new power bank with similar features (e.g. Xiaomi Mi Power Bank 3 Pro or Baseus) 20000mAh).
2. Use the old case for homemade assembly (install new cells and board with AliExpress).
3. Hand over the device to the recycling point – many stores (for example, the Messenger) accept old batteries with a bonus.

If you are buying a new power bank, pay attention to:

• 🔋 Capacity - the actual capacity must be at least 80% of the declared (checked by the tester).
• 🔌 Quick Charge 3.0 and Power Delivery).
• 🛡️ Protection against KZ, overheating and overcharging (should be specified in the characteristics).

FAQ: Frequent questions about power bank Xiaomi