Disassembly of Xiaomi power bank: detailed instructions with nuances for different models

Xiaomi power banks have long been the standard of reliability among portable chargers, but even they don't last forever. Over time, batteries lose capacity, connectors shatter, and the case can crack from a fall. Instead of buying a new device, many users prefer to disassemble the power bank to replace the battery, clean contacts or repair control boards. However, the process of disassembly carries risks from damage to thin plumes to short circuits when you carelessly handle lithium-ion cells.

In this article, we will discuss in detail how to properly open the case of power banks Xiaomi Mi Power Bank 3, Redmi 20000 mAh and other popular models, what tools you need, and what to look for to avoid turning the repair into a final breakdown. Special attention will be paid to safety, because improper handling of batteries can lead to fire. If you have never dealt with electronics, it is better to trust the dismantling specialist — but if you decide to act on your own, follow our recommendations.

Preparation for disassembly: tools and precautions

Before you take on the screwdriver, make sure you have everything you need. To disassemble the power bank, Xiaomi will need:

• 🔧 Plastic mediators or shoulder blades (for neat opening of the body without scratches). Metal tools can scratch the plastic and damage the internal components.
• 🔨 Set of screwdrivers (cross-haul) PH00 and flat 1.5 mm – the most popular sizes for power banks).
• 🔥 Thermoclee or bilateral scotch (for reverse assembly – the original adhesive often loses its properties after disassembly).
• 🧤 Gloves and safety glasses (lithium-ion batteries can release caustic substances when damaged).
• 📦 Container for screws (in order not to lose small parts - in power banks Xiaomi often uses screws of different lengths).

Also, prepare the workplace: the desk should be clean, without metal objects that could close the contacts of the battery. Never disassemble the power bank on a carpet or soft surface - static electricity can damage electronic components. If you are working with a model with a capacity of 20,000 mAh and above, remember: such batteries store a large amount of energy and can ignite if short circuit.

⚠️ Warning: If the power bank case is swelled or deformed, don't try to disassemble it! This is a sign of a battery failure, and any mechanical action can cause a fire.

Step 1: Opening the case - where the latches and screws are hidden

Xiaomi's power bank cases are assembled in two ways: on latches or on screws. Most modern models (for example, Mi Power Bank 3 10000 mAh) have a combined design - part of the body is held on latches, and part is fixed by screws under rubber legs.

1. Turn over the power bank and look at the bottom, and if you see rubber stickers or legs, you can gently put a plastic mediator on them, and screws are often hidden underneath them.
2. In Redmi 20,000 mAh models, the screws can be hidden under a technical information label, heat them with a hair dryer (temperature no higher than 60°C) and slowly peel them off.
3. Once you remove all the screws, take a plastic blade and gently run it around the seam of the body, starting at the corner, and the latches are usually located around the perimeter, and you need to snap them off one by one.

Don't use excessive force - if the case doesn't lend itself, you missed the screw or latch. Mi Power Bank Pro models sometimes use adhesive on the circuit, and you'll need to heat the hairdryer to open it (but not more than 70°C to avoid damaging the battery).

Step 2: Battery Removal: Top Risks and Rules

Once the top cover is removed, you'll see the battery, control board and connecting plumes. The battery is the most dangerous component: it can't be pierced, bent or subjected to mechanical stress. Xiaomi power banks typically use 18650-format lithium polymer cells or flat "packages" (in high-capacity models).

To remove the battery:

1. Disconnect the plume that goes from the control board to the battery, and it can be soldered or connected through a connector, in the first case you need a soldering iron, in the second case, carefully pull the plastic tongue.
2. If the battery is glued, do not try to tear it off by force. Use a plastic blade and slowly poke around the edges, warming up with a hair dryer (maximum 60°C).
3. In Redmi 20,000 mAh models, there can be two batteries connected in parallel, and you have to take them out one by one without closing contacts.

⚠️ Warning: If the battery shows signs of bloating, oxidation or damage to the shell, immediately stop disassembling! This battery cannot be used - it must be disposed of in special hazardous waste reception points.

Once the battery is removed, place it on a non-combustible surface (like ceramic tiles) away from metal objects. Even a discharged battery can retain residual charge and cause a short circuit when in contact with conductive materials.

Step 3: Diagnostics of the Control Board – What to Check First

The control board (or PCB - Protection Circuit Board) is responsible for charge/discharge control, overheating and short circuit protection, and 80% of power bank failures are related to it.

• 🔍 Darkened or bloated capacitors - a sign of overheating.
• 🔥 Burned tracks – often due to voltage surges.
• 💧 Traces of corrosion – if the power bank was exposed to moisture.
• 🔌 Oxidized contacts – especially on USB Type C or Micro USB connectors.

To check the board's performance, you'll need a multimeter. Set the resistance measurement mode and check:

• Resistance between + and - battery terminals (should be at least 10 kOhms - if less, there is a leak).
• Exit voltage USB-port (must be consistent with the stated: 5V, 9V or 12V model-wise).

If the board is visually sound but the power bank is not working, the problem may be the controller’s firmware, which requires a programr flashing (e.g., CH341A), but this is a topic for a separate article.

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Before you test the board with a multimeter, discharge static electricity by touching a grounded metal object with your hand, which will save the sensitive components from damage.

Step 4: Replacing the battery – how to choose a similar and not make a mistake

If the original battery fails, it can be replaced with a new one, and the main thing is to choose a full analogue in capacity, size and type. For power banks Xiaomi suitable batteries of the following types:

When buying a new battery, pay attention to:

• 📏 Dimensions – they must match the original to a millimeter, otherwise the case will not close.
• 🔋 Discharge current – for quick charging (Quick Charge) you need a battery with support for high currents (for example, 2C or 3C).
• 🔄 Availability of protection – some cheap counterparts do not have built-in protection against overcharging.

After installing a new battery, check the polarity of the connection! Incorrect connection will short circuit and fail the control board. If you are not sure, take a picture of the original pattern before turning off the old battery.

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When replacing the battery in Xiaomi power banks, be sure to use thermal glue for fixing - this will prevent the battery from shifting during falls and vibrations.

Step 5: Building a Powerbank – How to Avoid Mistakes

The assembly should take place in reverse order, but taking into account several nuances:

1. Before installing the lid, make sure that all the plumes are tightly connected and the battery is not shifted. In Redmi 20,000 mAh models, make sure that the two batteries do not touch each other with metal parts.
2. If the original screws are damaged, replace them with new ones of the same length. Too long screws can break through the board or battery!
3. To seal the case, use thermal adhesive (e.g., B-7000) or 3M double-sided tape. Silicone sealant is not suitable - it does not provide sufficient fixation.
4. After assembly, leave the power bank for 1-2 hours under the press (for example, under a stack of books) so that the glue is well grasped.

Before first use, fully charge and discharge the power bank 2-3 times, this will help calibrate the capacity controller.

• The correct connection of the battery (polarity!).
• The integrity of the plumes (perhaps they are not fully inserted into the connectors).
• The voltage at the output of the control board (should be ~3.7V at the battery terminals).

⚠️ Warning: If the power bank gets too hot or doesn't hold the charge after assembly, immediately disassemble it and check the quality of the connections!

Frequent Mistakes and How to Avoid Them

Even experienced craftsmen sometimes make mistakes when disassembling power banks, and here are the most common ones and ways to prevent them:

• 🔧 Shooting the screws, use a magnetic-tipped screwdriver and don't use too much force. If the screw doesn't go, drop it. WD-40 And wait 5 minutes.
• 🔥 Train damage -- never pull the wires! Only take the plastic connectors.
• 💥 Short circuit – before work, remove metal jewelry (chains, bracelets) and use a dielectric mat.
• 📉 Loss of capacity after repair – if the new battery is discharged quickly, check the leakage current with a multimeter (should be no more than 0.01 mA when off).

Another common problem is that the lid doesn't fit tightly after assembly, and this happens if you:

• Not all the slats have fallen into place (check if there are any slats).
• Too much glue – excess can interfere with closure.
• The body is deformed (for example, after a fall), in which case you can bend the plastic with a hairdryer a little.

If you have been cleaning the power bank for contacts, do not use alcohol or acetone - they can damage the plastic, preferably use isopropyl alcohol (99%) or a special liquid for cleaning contacts (for example, Contact Cleaner).

FAQ: Answers to Frequent Questions