There are many reasons to take apart the Xiaomi overbank, from replacing a bloated battery to repairing the USB-port or charging controller. However, the process requires care – wrong actions can lead to short circuit, damage to the board or even fire. In this article, we will discuss in detail how to safely open the case of popular Mi Power Bank models (including the Pro, 3, 4 and Redmi), which tools will be required and what to look for when you reassemble.
It is important to understand that most Xiaomi overbanks have adhesive housing or latch fixation, and some models (for example, Mi Power Bank 3 Pro 20000mAh) are equipped with additional screws under the seal. We will consider universal disassembly methods, as well as nuances for specific series. If you have never repaired electronics, we recommend first familiarize yourself with frequent mistakes of beginners at the end of the article.
Preparation: security tools and measures
Before you start disassembling, make sure you have everything you need, and the lack of the right tools is the main cause of damage to the body or internal components.
- 🔧 Plastic mediators (or guitar mediators) – to disconnect latches without scratches.
- 🔨 Thin screwdriver (cross or flat, depending on the model).
- 🧲 Magnetic substrate or screw container – to avoid losing small parts.
- 🔥 Multimeter – to check the voltage on the board (optional, but recommended).
- 🧴 Isopropyl alcohol (90%+) - for cleaning contacts or removing glue residues.
- 🛡️ Protective gloves – Li-ion batteries can be dangerous if damaged.
Also, prepare the workplace: the desk should be clean and well lit. Use an antistatic mat if you have one, it will protect the board from static electricity. Never disassemble a verbank on a soft surface (sofa, carpet) - a lost screw or spring can shorten the fee when assembled.
⚠️ Warning: If the battery of the superbank is swelling or deformed, do not try to disassemble it yourself! In such cases, there is a high risk of fire. Contact the service center or dispose of the device according to local regulations.
Step 1: Determination of the type of attachment of the shell
Xiaomi’s hulls are fixed in three main ways:
- Latches are the most common option (e.g. Mi Power Bank 2/3 10000mAh) and the case consists of two halves that are held on plastic clips.
- Fill screws – found in high-capacity models (e.g. Mi Power Bank 3 Pro 20000mAh or Redmi 10000mAh) screws are usually hidden under stickers or rubber legs.
- Glue - used in some budget models (for example, Mi Power Bank 1S) requires careful warm-up with a hair dryer.
To determine the type of attachment of your model:
- Turn over the verbank and look at the seam between the halves of the body, and if you see a gap, it's probably latches.
- Check for stickers or rubber legs - screws may be hiding under them.
- Try to squeeze the body slightly on the sides. If the halves are playing, they're latches; if the body is monolithic, maybe screws or glue.
Step 2: Disassembly of the case on the latches (Mi Power Bank 2/3, Redmi)
If your superbank is holding on to latches, follow this instruction:
- Insert a plastic mediator in the seam between the halves of the body on the side (where there are no ports).
- Carefully drive the mediator along the seam, alternately clicking clips. Start at the corner, there is minimal resistance.
- Once one side opens, do the same thing on the opposite side. Don't pull the body by force, it'll break the latches!
- When all the clips open, remove the top cover. Be careful: it may be glued to the indicator film (in some models).
Typical problems in disassembly:
- 🔧 Broken latches -- if you pull the lid by force, the clips break off, and then you have to glue it together when you build it.
- 🔋 A damaged battery -- if the mediator slips and pierces the battery, it's dangerous! Hold the tool parallel to the body.
- 📱 Severed indicator wires — In models with LED- indicators (e.g. Mi Power Bank 3), wires can be soldered to the board. Don't pull them!
Check the lack of charge in the device (discharge to 0%)
Prepare plastic mediators (2-3 units)
Check the body for cracks or swelling
Put soft cloth under the overbank to protect the screen (if any)-->
After removing the cover, you will see:
- Battery (usually 18,650 or 21,700 form factors)
- Controller board with USB- ports and control chip.
- Wires connecting the battery to the board (red - "+", black - "-").
- Charge indicator (if any).
Step 3: Disassembly of cases on screws (Mi Power Bank Pro, high-capacity models)
Helical mount models (e.g. Mi Power Bank 3 Pro 20000mAh or Redmi 20000mAh) are more difficult to disassemble due to hidden mounts.
- Remove all the stickers and rubber legs from the bottom of the case, and there are usually screws underneath.
- Use a thin screwdriver to gently fit the stickers. Don't scratch the case!
- Unscrew all the screws. Some models can have different lengths, remember which one came from.
- Once the screws are removed, the body can still hold onto the latches. Use the mediators as in the previous step.
Features of screw models:
- 🔧 Screwdrivers often have a special head (like a Tri-wing or a Pentalobe). If your screwdriver doesn't fit, don't try to force it, buy the right bit.
- 🔋 Batteries in high-capacity models can be soldered into a block (e.g., 2× 21700 cells). Don't break the connections between them!
- 📏 The controller board may be secured by additional screws or double-sided tape.
⚠️ Warning: Some Xiaomi models have warranty seals on their screws, and if they are damaged, you can cancel the warranty. If the device is warranty, contact the service center instead of repairing it yourself.
Step 4: Work with adhesive housings (Mi Power Bank 1S and others)
Adhesive housings are the hardest to disassemble, and it takes patience and accuracy.
- Warm the body seam with a hair dryer (~60°C) for 1-2 minutes. This will soften the glue.
- Insert a plastic mediator into the seam and slowly lead it along, separating the halves.
- If the case fails, reheat. Don't use metal tools, they'll scratch the plastic.
- After the body is separated, remove the residues of the glue with isopropyl alcohol.
Tips for glue models:
- 🔥 Do not overheat the case - high temperatures can damage the battery.
- 🧴 Do not use acetone or solvents to remove glue – they will damage the plastic.
- 🔧 When reassembling, use double-sided tape 3M instead of glue, which will make it easier to disassemble.
What to do if the body does not separate?
Step 5: Diagnostics and repairs of internal components
After opening the case, you can start to diagnose, and here are the most common problems and ways to fix them:
| Problem. | Possible cause | Decision |
|---|---|---|
| No charge from the grid. | Damaged. USB-port | Check the port for dirt/oxidation. solder a new port or replace the board. |
| It doesn't give power to the devices. | Failed discharge controller or damaged battery wires | Call the battery circuit with a multimeter to the USB- port, replace the damaged cells. |
| It's discharged fast. | Battery wear or high self-discharge | Replace the battery with a new one (suitable capacity and form factor). |
| Bloated battery | Overheating or deep discharge | Dispose of the battery immediately! Don't use bloated batteries. |
| The charge indicator is not working. | The indicator wires were broken or the fee was faulty | Seal the wires back or replace the display fee. |
For battery replacement:
- Disconnect the wires from the old battery (remember the polarity!).
- Carefully remove the battery. If it's glued, use isopropyl alcohol to soften the glue.
- Install a new battery of the same capacity and size, connect the wires to polarity.
- Secure the battery with double-sided tape or heat glue.
⚠️ Warning: When soldering wires to the board, use a soldering iron of no more than 30W and a flux-based rosifoli. Overheating can damage the controller's chips!
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If you're replacing a battery, choose a battery with a protective board (PCM) that prevents overcharging, deep discharge and short circuit. Non-PCM batteries are cheaper but dangerous to use.
Step 6: Reverse Assembly and Performance Check
The assembly of the superbank should be in reverse order.
- Make sure all wires are connected correctly (especially battery polarity!).
- If the body was held on latches, check their integrity. Broken clips can be replaced with a drop of superglue (but this will complicate future disassembly).
- Twisting all screws (if any) Don't pull over - it could damage the thread.
- Before final assembly, turn on the overbank and check: Charging from the mains (the indicator should burn). Charging to the device (try to connect the phone).
If the verbank does not work after assembly:
- 🔋 Check the polarity of the battery connection - overflow will disable the controller!
- 🔌 Make sure the controller board fits tightly to the housing (sometimes you need to press it to contact).
- 📱 Call the multimeter circuit from the battery to the USB- port for a cliff.
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Once assembled, let the verbank work 10-15 minutes idle (without connected devices), which will allow the controller to "see" the new battery and adjust the charge indication.