Decoding Fast Charging Technology: From USB-C to GaN Revolution

In today’s fast-paced world, charging speed is crucial for electronic devices, making fast charging technology a hot topic. This article delves into fast charging technology from three perspectives: fast charging protocols, GaN technology, and safety risks.

I. Fast Charging Protocol Comparison

The current market offers various fast charging protocols, such as PD 3.0/3.1, QC 5.0, and PPS, each with its own strengths.

• The PD 3.0 protocol supports up to 100W power, capable of charging most laptops to around 50% in 30 minutes. PD 3.1 extends this further, supporting up to 240W and significantly improving charging speed. For a 16-inch laptop, PD 3.1 can charge it to approximately 70% in one hour, a 30% efficiency improvement compared to PD 3.0.
• As Qualcomm’s fast charging solution, QC 5.0 supports up to 100W, with strong compatibility. Some Android phones from Xiaomi and Lenovo, when paired with a QC 5.0 charger, can charge to around 40% in just 15 minutes.
• The PPS protocol stands out for its flexibility in precisely regulating voltage and current. For instance, Sony cameras matched with PPS protocol chargers can operate while charging with stable power supply, improving charging efficiency by about 20% compared to regular protocols.
• Smartphones and laptops need to match specific protocols to charge at full speed, as different protocols have varying requirements for voltage, current, and data handshaking. Take the Xiaomi 13 Pro as an example. Equipped with Xiaomi’s self-developed Surge P1 fast charging chip and PD protocol, it can charge to 50% in 15 minutes with the original 120W PD charger. However, using a charger with an incompatible protocol will significantly reduce charging speed or even prevent normal charging.

II. Gallium Nitride (GaN) Technology

• GaN chargers can achieve small size and 100W+ high power output, mainly due to the material’s properties. GaN material has an electron mobility 1,000 times higher than silicon, allowing chargers to operate at high frequencies with low loss and high efficiency. Compared to traditional silicon-based chargers, GaN chargers can reduce size by 40% -50%. For example, a 100W GaN charger measures about 60×60×30mm, while a silicon-based charger of the same power is about 80×80×40mm.
• Under 110V input, GaN chargers can achieve a conversion efficiency of 92% -95%, an improvement of 10% -15% over silicon-based chargers. They also generate less heat, further enhancing charging efficiency.

III. Safety Risk Warning

• Poor-quality chargers often cause battery swelling due to the lack of overvoltage and overheating protection. When overvoltage occurs, the charger’s output voltage exceeds the device’s tolerance. For example, when charging a 5V-input phone, an inferior charger may output 6V-7V, causing chemical imbalance in the battery. Electrolyte decomposition produces gas, leading to swelling. The absence of overheating protection can cause heat accumulation from prolonged charger operation. If the battery temperature exceeds 60°C, the internal separator melts, causing positive and negative electrode short-circuiting and swelling.
• Certifications like UL, FCC, and CE are crucial. UL certification comprehensively tests the electrical safety, fire resistance, and mechanical strength of chargers. Chargers passing UL certification meet standards for electrical clearance and creepage distance, reducing electric shock and fire risks. FCC certification focuses on electromagnetic interference, ensuring chargers do not interfere with nearby electronic devices. CE certification covers electromagnetic compatibility and low voltage directives, providing all-round safety and reliability for chargers.

IV. Fast Charging Technology Application Scenarios

• Smartphones: Fast charging technology enables quick battery top-ups during short intervals. For instance, if a user wakes up to find their phone below 20%, a 65W charger supporting the PD 3.0 protocol can charge it to around 70% in half an hour, meeting daily usage needs.
• Notebooks: High-power fast charging significantly reduces laptop charging time. The 2022 MacBook Pro paired with a 140W GaN charger can reach about 80% in one hour, nearly 30 minutes faster than the traditional 67W charger, improving work efficiency.
• Tablets and Cameras: Fast charging is also widely used for tablets and professional cameras. The iPad Pro can charge to about 60% in 45 minutes with a 96W charger supporting USB-C Power Delivery. Sony Alpha series cameras, matched with PPS protocol chargers, allow shooting while charging, meeting professional photography demands.

V. Fast Charging Technology Industry Trends

• Higher Power popularity: Future fast charging will move toward higher power. Some phone manufacturers have already launched 200W+ fast charging, capable of charging phones to over 80% in 10 minutes. As technology advances and costs decrease, high-power fast charging will become more widespread across devices.
• Multi – device Compatibility: Fast charging protocols will further unify to achieve multi – device compatibility. The USB-IF organization’s promotion of the USB Power Delivery standard aims to allow different brands and types of devices to use the same fast charging solution. In the future, a phone charger could fast charge laptops and tablets, enhancing user experience.
• Intelligent Control: Fast charging will integrate intelligent control features. Chargers can automatically adjust charging strategies based on device battery levels and health status for safer and more efficient charging. With IoT technology, users can remotely control charging progress via their phones, further boosting convenience.

Fast charging technology is revolutionizing how we charge electronic devices. From the popularity of USB-C to the application of GaN technology, despite potential safety risks, following standards and choosing compliant products allows us to enjoy the benefits of fast charging. As technology develops, fast charging will play a more important role in various scenarios, bringing more convenience to our lives.