Open up the shell of a power bank or wireless earbud case and you’ll find yourself looking at somewhere between 40 and 80 discrete line
items in the supply chain. Cells, voltage sensors and thermistors, a buck-boost controller, MCUs, connectors, MLCCs, resistors and more. In electronics, the real business risk isn’t just the total count of parts – although it is true that the more inputs you have, the more points of failure there are – but that all too often it is the cheapest, most forgettable part that has the fewest suppliers and the longest lead times.
In this article, we’ll go through the imagined teardown of a typical electronic accessory – in this case, a power bank – and look at the sourcing issues around what’s inside.
The Teardown: Following One Product From Shell to Software
Let’s take the Xiaomi Built-in Cable Power Bank 10000 Pocket Edition 2026 as our example product – a recent enough product that could easily
be found on desks or in laptop bags around the world. This product provides 22.5W MAX fast charging through its integrated USB-C charging cable,
independent USB-C port and a USB-A port all able to be used concurrently. It is compatible with protocols including PD3.0, PPS, QC4, FCP, and SCP.
Enclosure & mechanical layer
Starting from the outside we have injection-molded housing, screws and adhesive, buttons and indicator lights. All these components are
relatively low-risk due to their ubiquity, even if those in your product are custom-made, and have high substitutability if the need arises.
Battery pack & protection
Pry open the housing and you’ll see the battery cells and PCBA. A thermal pad blankets the mainboard, conducting heat outward. The top
and sides of the battery cell are cushioned with foam and potting compound.
The primary options available for battery pack potting are silicone and polyurethane (PU). The former is generally better for maximum
shock absorption and heat tolerance. Look for a low Shore A hardness (e.g., Shore A 30 to 50) formulation. This softness allows the material to cushion components against severe impacts while absorbing the micro-expansions and contractions that battery cells undergo during charge cycles.
Polyurethane strikes a functional balance between rigid structural support and shock absorption, making it effective for portable electronics. It sticks well to the plastics and aluminum commonly used in battery housings, forming a reliable perimeter seal. For high vibration resistance, choose a PU compound with high elongation at break (around 100%). This prevents the compound from tearing when subjected to high-G forces or drops.
To prevent thermal runaway, choose a compound with a rating of at least 0.8 W/m·K to ensure heat is successfully moved away from the
battery core while it cushions the pack. For flame retardancy, ensure the material carries a UL 94 V-0 rating, meaning it is self-extinguishing and will
inhibit fire propagation if a cell fails.
The battery pack itself may come in all manner of configurations, from cell chemistry (Li-ion vs. LiFePO4), to cell brand (e.g. ATL in the Xiaomi Built-in Cable Power Bank 10000 Pocket Edition 2026), and pack configuration. This is an element that is very much a commodity but is certification-heavy when it comes to sourcing for your target markets.
Power path electronics
The PCBA sits alongside the battery pack, which has its edges wrapped with high-temperature insulating tape to prevent short circuits with main board components. The power bank SoC relies on the SOUTHCHIP SC2017A, which integrates the buck controller and MCU into a single integrated circuit (IC). This is a common trend in 2026, with single-vendor chipsets serving multiple functions, which reduces bill of materials (BOM) count and thereby concentrates risk into fewer parts. In this product, the chip reduces peripheral component counts through a built-in USB PD baseband physical layer, Type-C detection, VBUS discharge path, VCONN power suppy and protection circuits. Its internal MCU subsystem has a 32-bit ARM
Cortex-M0 core, with built-in 128KB Flash and 8KB SRAM.
A WCH CH32X035 MCU handles intelligent battery telemetry and status transparency, backed by an iCM CM1003-BZS lithium protection IC.
Power components include a step-down MOSFET, VBUS MOSFET and lithium-battery protection MOSFET, as well as a filtering capacitor.
The invisible layer: passives
Hundreds of MLCCs, most under $0.10 each, quietly required for power integrity everywhere on the board.
The Bottleneck Isn't (Always) Where You'd Expect
Multi-layer ceramic capacitors (MLCCs), for example, sit on nearly every power and signal rail, cost pennies, and in 2026 became formally allocated at Murata and Taiyo Yuden – two Japanese electronics giants that dominate the global market for MLCCs together with Samsung Electro-Mechanics
(SEMCO – due to AI server demand pulling capacity away from consumer-grade parts. High-capacitance 10μF+ parts in 0402/0603 packages are running 20–52 week lead times.
Think back to the Nexperia dispute and we can see mature-node squeeze pulling capacity from ordinary power-management and logic chips used in consumer electronics – not just AI chips, even though they may be the hot-button issue du jour. Risk does not scale precisely with cost. A $0.12 capacitor used 40 times per board, sole-sourced, with no qualified second source, is a bigger threat to production than a $9 Bluetooth SoC with three
interchangeable vendors.
Example Component Risk Analysis
Battery Cell
Single-source in practice. Fixed physical cavity dimensions mean other cells won't fit without changing the plastic tooling. Typical lead item is 16–24 weeks. Allocation status is stable but sensitive to airline shipping regulations. Switching would mean a full redesign taking perhaps 3–6 months, as changing the cell requires structural plastic modifications and mandatory UL2054/UN38.3 safety re-testing.
System-on-Chip (SoC)/Controller IC
Sole-source: The layout relies heavily on the specific pinout, switching frequency, and thermal pad setup. Frequently put on formal allocation, this is a hgh-risk component with a lead time of 26–52 weeks. Switching means a full redesign, requiring PCB layout modification, thermal loop profiling, and full CE-RED / FCC / UL62368-1 safety re-certification.
Specific MLCC Value
E.g. High-voltage DC filter or snubber capacitor – single-source in practice. Multiple vendors make it, but likely only one distributor has active stock.Some types are currently on formal allocation. Commodity, low-capacitance MLCCs remain stable at baseline lead times of 8 to 12 weeks, but high-capacitance, high-voltage, and specialized automotive/AI-grade parts are heavily constrained, with factory lead times stretching from 26 up to 52 weeks. Replacing this part is a drop-in swap of 1–2 weeks. Simple alternate vendor part approval requires basic automated optical inspection (AOI) change and a thermal bench test.
Bluetooth Module
A smart connectivity chip found in premium app-controlled or IoT chargers. Single-source in practice, limited by embedded firmware code and specific onboard trace antenna tuning. Normal lead times run 12 to 20 weeks. These parts often see minor soft-allocations. Replacement is a pin-compatible swap (2–4 weeks). If the firmware can be easily ported, you only need to run basic RF emissions tests without changing the plastic case.
MLCC and SoC/controller unavailability would represent the biggest headaches in a line-down situation. For the MLCC allocation, you would need to work with your manufacturing partner to immediately approve alternative voltage ratings (e.g., qualifying a 630V part to replace a 400V part) or slightly different footprints (e.g., stepping up from 0805 to 1206 footprint if the PCB pads allow it), to keep the factory running without delaying shipment.
When a System-on-Chip (SoC) or primary controller IC goes obsolete or becomes unavailable, it creates the most dangerous bottleneck in
hardware manufacturing. Because this chip directly controls high-voltage power conversion and thermal safety, changing it is never a simple software fix. If the SoC/controller becomes unavailable, because a controller change forces a total re-certification, look into buying broker stock or an alternative "Option B" PCB layout that accepts a more widely available, industry-standard controller.
Broker Stock
When traditional authorized distributors (like Arrow, Avnet, or DigiKey) quote a 52-week lead time that your supply chain can’t handle, you
are forced to step into the open market. Independent distributors – brokers – buy excess inventory from factories and resell it at a premium. The advantage for sourcing teams here is that, crucially, they have the stock. Even if it is at a price point you wouldn’t normally accept. The risk lies in counterfeits and degradation. The open market is flooded with counterfeit chips, sanded-down fake parts, or chips salvaged from recycled electronics. For a phone charger plugged into a wall outlet, a fake controller can cause catastrophic fire or shock hazards. To safely use broker stock, you must route the parts through a certified third-party testing house before they reach your factory. They must perform X-ray inspection to verify the internal silicon die matches an original factory reference, acetone swipe testing to ensure the chip's surface hasn't been chemically erased and re-printed with fake part numbers and de-capsulation (acid etching), opening a sample chip to visually read the manufacturer's logo printed directly on the silicon wafer.
“Option B” Layouts
Instead of waiting for a factory shutdown, it is possible to design a single circuit board that can accept two different chips depending on what is available. Designers overlap the copper pads on the PCB. The inner ring of pads fits your primary, preferred Controller A. A wider, outer ring of pads
fits Controller B (a highly available, industry-standard generic alternative).
Because different chips route their power, ground, and feedback pins differently, engineers place tiny, zero-ohm resistors (essentially micro-jumpers) around the chip. If Controller A is in stock, the factory populates the board one way. If Controller A vanishes, the factory updates the automated
pick-and-place machine program to drop Controller B onto the board and shifts the jumpers to route the signals to the new pins.
The catch is upfront testing. You must pay for and clear both configurations through safety agencies (UL, CE, FCC) in advance. While it doubles your initial certification costs, it eliminates future line-down situations for this component.
Conclusion
The question when looking at your BOM isn't "how many parts does this product have?" but "which of these parts, if it disappeared tomorrow, stops the line – and how long would it take to recover?" With some industry analysts now forecasting MLCC tightness turning into a full-on shortage in 2027, now is the time to look at the manufacturing inputs of your electronic products and assess not by cost alone but by risk-adjusted cost. Preparation will help you ensure a bottleneck doesn’t turn into a crisis.
