Why can't some PD chargers work at full load for a long time?
In today's consumer electronics market, price wars are shrouded in smoke. As an OEM manufacturer or procurement manager, you may often face the confusion of: "Why is my supplier's quote so much lower than peers, but the product can still meet the requirements in actual charging tests for 3C products? ”This phenomenon is particularly common in the field of PD chargers. A 140W charger that appears to meet all parameters performs perfectly in short-term testing, but frequently malfunctions and even shuts down directly during high load, long-term full load testing, or long-term operation, resulting in unstable quality and short lifespan.
This is not just a simple performance issue, but also hides serious quality and safety risks. Behind the cheapness are often power exaggeration, insufficient component specifications, and compromises in heat dissipation design.
To help you identify these potential pitfalls, this article will delve into several key reasons from a technical perspective that prevent PD chargers from working at full load for extended periods of time, and share the secrets to identifying truly reliable products. We will discuss through a practical case - we recently collaborated with a client to uncover reliability issues hidden beneath these surface prices through rigorous full load testing.
Behind Overheating Protection (OTP): Insufficient Component Selection and Heat Dissipation Design
Some high-power gallium nitride PD chargers have high power density, which means that a large amount of electrical energy is compressed into a small volume and converted into heat energy. When the PD charger operates at full power, a large amount of heat is generated inside. When the product operates under continuous high load, the junction temperature of these components will rapidly rise. In order to prevent core components such as driver ICs and power devices (such as MOSFETs, GaN) from being damaged due to overheating, almost all chargers are equipped with built-in thermistors (NTC) or temperature protection functions in ICs to monitor temperature. Once the temperature (usually around 90-110 degrees Celsius) exceeds the set safety threshold, the OTP protection circuit will automatically activate, cutting off voltage and current output, thereby achieving shutdown protection. This is also the most common reason.
So, why do some chargers trigger overheating protection in just 20 minutes? This is usually caused by the following three key factors:
Insufficient component specifications: Under cost pressure, some manufacturers may choose core components with small specification margins (such as main capacitors, switching tubes, rectifiers, transformers). These components may barely meet the standards in short-term testing, but if the temperature rises too quickly under long-term full load, they can quickly trigger protection.
Unreasonable heat dissipation design: The heat dissipation design of the internal space of the charger is also crucial. If the shell material has poor thermal conductivity, the internal components are tightly arranged, or there are not enough heat sinks, improper application of thermal grease, or there is no material with sufficient thermal conductivity, then heat cannot be effectively dissipated. This will cause heat to continuously accumulate inside the charger, ultimately triggering protection.
Our product design philosophy is aimed at fundamentally solving these problems. We always insist on using high specification components with sufficient power and temperature tolerance to ensure the stability and reliability of our products under high loads from the source. At the same time, our engineers conduct rigorous heat dissipation simulations and physical tests in the early stages of design to optimize the internal structure and heat dissipation scheme, ensuring that our charger can maintain a stable low temperature and avoid overheating risks even after more than 10 hours of continuous full load operation.
From "peak power" to "sustained power": the trap of power virtual scaling
In the technical specifications of PD chargers, there are two crucial concepts: peak power and sustained power. The 140W power advertised by many manufacturers may only be the peak power that can be achieved in a very short period of time, rather than the sustained power that can be stably and long-term output. This is a common industry gray area. In industry practice, for fast charging chargers for laptops and mobile phones, the design goal is to meet the short-term peak power requirements of the device (such as high load operation of laptop CPU/GPU) and long-term high-power charging, but considering heat dissipation and volume, allowing for safety maintenance through frequency reduction and protection under continuous extreme conditions. This is different from industrial power supplies that supply power to servers and radios. The design goal of those power supplies is 7X24 full load operation, with a large margin for heat dissipation and components, resulting in much higher volume and cost. If the concepts of peak power and sustained power are not clear and appropriate power sources are not selected correctly, it can also be the fundamental reason for frequent problems in many products in practical applications.
The most serious situation is power false labeling. How is this power virtual scaling achieved? Usually, manufacturers sacrifice the reliability margin of components to achieve the nominal maximum voltage and current at the moment of testing. However, this design is like installing an unsustainable engine on a racing car, which can only cause short-term bursts. Once the sustained high load exceeds the set threshold, in order to protect the internal circuit, the charger will immediately trigger over power protection (OPP) or over-current protection (OCP), resulting in output interruption.
Our recent test precisely proved this point. In a collaborative test with a customer, we found that a competitor's nominal 140W charger stopped voltage and current output after only 20 minutes of operation under full power 28V 5A test conditions on an electronic load meter due to triggering the protection function. The normal operation time at full load is too short, which cannot meet the safety requirements. This is a typical case of power virtual labeling, and it reminds us once again that just looking at the parameter table is far from enough.
Adhering to standards and quality: why UL standards are crucial
Simply focusing on price and nominal power is far from enough when choosing suppliers. A truly trustworthy product must be supported by strict safety standards. As a leading global safety science company, UL (Underwriters Laboratories) certification not only represents basic safety guarantees, but also reflects the rigorous testing of product design, component selection, and manufacturing processes.
Following UL standards means that products must undergo a series of rigorous tests, including longer and more rigorous full load and aging tests. This is fundamentally different from the simple functional testing or short-term full load testing that many manufacturers only conduct. UL standards require products to maintain stable and safe operation even in simulated harsh usage environments. This persistence in detail and reliability is the fundamental guarantee for high-quality products.
In sharp contrast, our 140W PD3.1 chargerdesigned according to UL standards remained stable and normal even after more than 10 hours of continuous operation under the same full load conditions. This is not only a performance victory, but also a strong proof of our commitment to product quality. We deeply understand that providing customers with not only low prices, but also durable and reliable solutions is our greatest value.
Conclusion: It's not just about price, but also a long-term value investment
Through the above analysis, it is not difficult to find that whether a PD charger can work stably for a long time under high load depends not only on its nominal power value. Behind the cheapness, there are often a series of technical traps such as overheating protection, power false labeling, and insufficient component specifications. These issues not only affect product performance, but may also pose quality risks to your end products and even damage brand reputation.
Therefore, as an OEM manufacturer and purchaser, we strongly recommend that you shift your focus from a single price to deeper value considerations when selecting suppliers. In addition to focusing on the continuous power of the product, it is also important to examine the selection of its components, the rationality of its heat dissipation design, and whether it complies with strict industry standards such as UL standards. These invisible details are the key to ensuring the long-term reliability of the product.
Nowadays, what your customers need is not just a functional charger, but a reliable partner who can provide stable, safe, and long-lasting power. Do you really know the product you are purchasing?
We are always committed to providing customers with high-quality and reliable PD charging solutions, and look forward to establishing a long-term and mutually trusting cooperative relationship with you to jointly create truly competitive products.
Shenzhen Aieco Electronics Co., Ltd
Address:1531 Beiterui New Energy Technology Building, Dongkeng Community, Fenghuang Street, Guangming District,Shenzhen 518107
Contact: Bill Lau
Cellphone(wechat):+86- 137 1525 3076
Website: http://www.aiecopower.com Email: info@aiecopower.com
