The Billion-Dollar Confusion
In the global electronics market, there is a persistent gap between what is printed on a box and what the user experiences. You buy a power bank labeled “20,000mAh,” expecting four full charges for your smartphone, but it dies after barely two.
Is the industry dishonest? Or is there a deeper technical reality that buyers are missing?
As a premier PCBA (Printed Circuit Board Assembly) and OEM/ODM manufacturer based in Shenzhen, Honghao Electronics has spent years analyzing the delta between Nominal Capacity and Actual Output. In this guide, we will pull back the curtain on power bank engineering, revealing why most products fail capacity tests a
1. The Physics of Power: Why 10,000mAh Does Not Equal 10,000mAh
To understand why power banks “fail” tests, we must first understand the physics of energy conversion.
The Voltage Gap
Most lithium-ion battery cells operate at a nominal voltage of 3.7V. However, the USB standard for charging mobile devices is 5V (or higher for Fast Charging protocols like PD and QC).
When energy moves from the cell to your phone, it must be “stepped up” by the PCBA.
Energy (Wh) = Capacity (mAh) × Voltage (V)
A 10,000mAh battery at 3.7V holds 37Wh of energy.
When converted to 5V, the theoretical capacity becomes 7,400mAh (37Wh / 5V).
The Honghao Advantage: Many suppliers hide this calculation. We educate our clients. Any power bank that claims to deliver its full 3.7V capacity at a 5V output is mathematically impossible. We prioritize transparency by clearly marking Rated Capacity on our products, a move that builds long-term trust for your brand.
2. The Role of PCBA: The Efficiency Killer
The PCBA is the “brain” of the power bank. It manages the boost conversion, safety protocols, and thermal management. This is where most manufacturers fail the real-world test.
Energy Conversion Loss
No conversion is 100% efficient. Cheap PCBAs lose a significant portion of energy as heat.
Tier 3 PCBAs: 65% – 70% efficiency.
Standard PCBAs: 75% – 80% efficiency.
Honghao High-Performance PCBAs: 90% – 95% efficiency.
When a PCBA is inefficient, that lost energy isn’t just “gone”—it turns into heat, which degrades the battery cells and shortens the product’s lifespan. By utilizing high-quality MOSFETs and precision ICs in our PCBA production, Honghao Electronics minimizes resistance and maximizes output.
3. Why Most Power Banks Fail: 4 Critical Factors
A. Internal Resistance (The Silent Thief)
As battery cells age or if they are of “B-grade” quality, their internal resistance increases. During a high-current discharge test (like charging a tablet), high resistance causes the voltage to sag prematurely, forcing the PCBA to shut down even when there is still energy in the cells.
B. Poor Thermal Management
Heat is the enemy of capacity. If the PCBA design does not allow for efficient heat dissipation, the system’s thermal protection will throttle the output. Our engineering team at Honghao uses multi-layer PCB designs and advanced thermal pads to ensure the device stays cool even during 22.5W or 65W fast charging.
C. Inaccurate Fuel Gauges
Many power banks use cheap “voltage-based” LEDs to show battery life. These are notoriously inaccurate. At Honghao, we implement Coulomb Counting ICs in our PCBA designs, which measure actual current flow for a precise digital readout.
D. The “Recycled Cell” Epidemic
To hit ultra-low price points, some factories use recycled cells from electric vehicles or laptops. These cells may show a high voltage initially but fail immediately under a load test.
4. Beyond the Power Bank: Honghao’s Multi-Sector Expertise
Our technical mastery isn’t limited to portable chargers. We apply the same rigorous standards to our entire product ecosystem:
Invisible Long-Distance Wireless Charging: We solve the “efficiency gap” in wireless power. Traditional wireless chargers require perfect alignment. Honghao’s Long-Distance (Under-Desk) Wireless Chargers utilize high-Q factor coils and specialized PCBAs to maintain charging speeds through 20mm–45mm of solid wood or marble.
Smart Power Strips: Combining high-voltage AC with low-voltage DC (USB-C PD) requires sophisticated isolation. Our PCBA layouts ensure zero interference and maximum safety.
5. How to Source Quality: A Buyer’s Checklist
If you are an importer or a brand owner, how do you verify a factory’s claims?
1.Ask for the PCBA Conversion Rate
If they can’t give you a number, they aren’t the manufacturer.
3.The Weight Test
High-density lithium cells have a specific weight-to-energy ratio. If a “30,000mAh” power bank feels like a smartphone, it’s a fake.
2.Verify the Rated Capacity
Look for the “5V Output” capacity, not just the “3.7V Cell” capacity.
3.Certifications (UL, CE, RoHS)
Ensure the PCBA design meets international safety standards to avoid legal liabilities.
6. Why Choose Honghao Electronics?
In a market flooded with “fake numbers,” Honghao Electronics stands for Real Engineering.
We don’t just assemble parts; we design the core technology. Whether you need a high-conversion PCBA for a custom project, a reliable line of branded power banks, or cutting-edge invisible wireless charging for office furniture, we provide the technical backbone your business needs to scale.
Don’t let your brand fail the test. Choose the manufacturer that builds for reality.