$15 aliexpress 40W USB-C charger test

Summary

In this video, the creator tests a 40W USB charger with two USB-C ports, providing detailed insights into its performance. After initial testing, the charger is evaluated for its voltage outputs, current handling, and temperature during use. Despite the charger being able to supply the claimed outputs, it becomes quite hot under load, raising concerns about its long-term use. The video also dives into the internals of the charger, revealing its components and explaining the design behind the switching power supply and transformer. While the charger works as advertised, its temperature issues may limit its usability under high loads.

Takeaways

• 😀 The 40W USB charger has two USB-C ports and offers different output voltages: 5V, 9V, 12V, 15V, and 20V, with currents varying by voltage level.
• 😀 The charger was bought on AliExpress for around $15 and is being tested to determine if it performs better than a previous charger.
• 😀 The charger successfully detects and switches between charging protocols, with a maximum current of 3.3A at 5V, 3A at 12V, and 2.2A at 20V.
• 😀 After running the charger at full load for two hours, it heats up significantly, with temperatures reaching up to 111°C on the USB port.
• 😀 The internal components, including the primary switching chip and electrolytic capacitors, run hot, with the primary switching chip reaching 158°C.
• 😀 The charger has a well-designed transformer with good insulation to prevent interference, and it uses a synchronous rectifier for voltage conversion.
• 😀 While the charger can provide independent voltages for each USB-C port, it is not ideal for sustained full-load operation due to high temperatures.
• 😀 The LED indicator is poorly positioned and barely visible, especially in bright environments, making it less practical for users.
• 😀 The thermal performance of the charger can be improved by positioning it horizontally rather than vertically, as heat dissipation is hindered in its vertical position.
• 😀 Despite its shortcomings in temperature management and LED visibility, the charger is functional and capable of delivering the advertised power and voltages for short bursts.
• 😀 The design features, such as interference suppression, a fuse, and thermistor for current limitation, indicate the charger is reasonably safe, but the overall build quality could be improved.

Q & A

What is the primary feature of the 40W USB charger discussed in the video?

The 40W USB charger has two USB-C ports, a universal input, and can supply different voltage levels: 5V, 9V, 12V, 15V, and 20V. It supports a maximum of 3A at 5V, 2.66A at 15V, and 2A at 20V.

Where was the charger purchased, and how much did it cost?

The charger was purchased from AliExpress for approximately $15.

How did the charger perform under load tests in terms of voltage and current?

Under load, the charger performed well. At 5V, it supplied up to 3.3A; at 12V, the current was similar to 5V. It handled 15V at 3A and 20V at 2.1–2.2A, matching the claimed specifications for short-term use.

What issue was observed regarding the temperature of the charger during the tests?

The charger got very hot during the tests. After running for 2 hours under full load, the temperature on the USB port reached 101°C, and the primary switching chip reached 158°C, which could lead to overheating issues.

What was the performance of the LED indicator light on the charger?

The LED indicator was very faint and hard to see, especially in bright conditions. It was only visible in the dark, and its positioning was considered suboptimal.

How did the internal components of the charger respond to the heat during prolonged use?

The internal components, such as the primary switching chip and electrolytic capacitors, reached temperatures significantly higher than their rated limits, with the primary switching chip reaching 158°C and electrolytic capacitors reaching 116°C. This suggests that while the charger functions, its thermal management could be improved.

What did the thermal imaging reveal about the internal components of the charger?

Thermal imaging showed that several internal components, like the primary switching chip, secondary chips, and the transformer, were running extremely hot, indicating that the charger might not be optimal for sustained high-power use.

What was the construction design of the charger like?

The charger features a two-board design with various chips for voltage regulation and interference suppression. It uses synchronous rectifiers, buck regulators, and a flyback transformer. The transformer is well-designed with copper shielding to minimize interference.

How did the switching frequency change based on the load?

The switching frequency of the charger varied with the load. At full load, it operated at around 180kHz, and at lighter loads, the frequency reduced to around 26-30kHz, indicating dynamic adjustment of switching parameters based on load conditions.

What are some potential improvements for the charger based on the testing?

The charger could benefit from better heat dissipation, improved LED visibility, and more reliable solder joints in its internal components. Additionally, reducing the operating temperature at full load would increase its longevity and efficiency.