Evaluation of Raspberry Pi 15W Power Adapter: Fixed Plug Design for Home Charging

—Charger Head Network in-depth evaluation No. 1847—

Introduction

Recently, Charger Head Network got a Raspberry Pi 15W power adapter. Its design style is different from mainstream chargers, featuring an integrated USB Type-C charging cable, while the main body is compact and can be held with one hand. The fixed plug design is suitable for home charging, adapting to multiple scenarios for extended charging. Let’s take a look at the performance of this adapter from the perspective of Charger Head Network.

Unboxing Introduction

The Raspberry Pi 15W power adapter adopts a high flame-retardant PC material shell, with a fine-textured matte finish, and the overall design is pure white. Its appearance is different from mainstream chargers, featuring a square body and an integrated Type-C charging cable.

The square body has a large rounded edge transition, giving a warm hand feel, while the center area of the adapter’s front panel is embossed with the Raspberry Pi logo.

The plug part adopts a fixed PIN design, and the side panel is printed with the charger specifications.

Model: KSA-15E-051300HU;

Input: 1000-240V~ 50/60Hz 0.5A;

Output: 5.1V3.0A;

The main body is silk-screened with FCC, VI level energy efficiency, and other certification marks.

The main body and the cable are molded in one piece, and the connection point is reinforced to be more resistant to bending and swaying.

The integrated charging cable is printed with parameters such as “80℃” and “300V”.

The Type-C connector shell has the same appearance design as mainstream C to C cable terminals, and the connection point has a reinforced injection molding design for better wear resistance. Meanwhile, the internal Type-C connector uses a specially designed PIN.

The diameter of the integrated charging cable is approximately 3.24mm.

The length of the exposed part of the integrated charging cable is approximately 150cm.

The main body of the Raspberry Pi 15W power adapter is approximately 45.09mm in length.

The main body of the Raspberry Pi 15W power adapter is approximately 45.10mm in height.

The width (thickness) of the Raspberry Pi 15W power adapter is approximately 27.13mm.

The weight of the Raspberry Pi 15W power adapter is approximately 98.3g.

The Raspberry Pi 15W power adapter is relatively compact compared to a 1 yuan coin.

The Raspberry Pi 15W power adapter fits comfortably in the palm of an adult male’s hand, making it easy to hold with one hand.

Protocol Testing

Pursuing a complete exploration of the protocol is the significance of this test, allowing users to select devices based on specific protocols for a better fast charging experience.

Using the POWER-Z KM003C tester to test the integrated Type-C cable’s charging protocol, it was found to support the DCP charging protocol.

Product Testing

Next, let’s take a look at the specific user experience of this charger. Charger Head Network will provide a comprehensive understanding of this charger from compatibility testing, full charging process testing, standby power consumption testing, and conversion efficiency testing.

Charging Compatibility Testing

The compatibility testing phase clearly shows the charging situation of the charger for various devices. Charger Head Network will use dozens of devices to test the charger and present real testing data for readers.

Using the Raspberry Pi 15W power adapter to charge the iPhone 15 Pro Max, the actual input power at the phone end is 4.98V 2.95A 14.69W.

Using the Raspberry Pi 15W power adapter to charge the MacBook Pro 16 M1 Max laptop, the actual input power at the laptop end is 4.99V 2.86A 14.26W.

In addition, charging the Lenovo Xiaoxin Pro 14 laptop resulted in no charging input, meaning it could not be charged.

Summarizing the charging data of the above mainstream terminal devices, it can be seen that most mobile devices handshake at the 5V voltage level, while for laptop devices, it does not meet the charging specifications of some models, thus unable to charge.

Plotting the charging power data as a bar chart shows that the output performance can be divided into 5W, 10W, and 15W levels. The charging power for Apple devices is relatively high, but it remains in a normal charging state.

Full Charging Process Testing

The Raspberry Pi 15W adapter has a maximum single-port output power of 20W. The Raspberry Pi 15W adapter and the iPhone 15 are placed in a 25℃ constant temperature chamber, and the power is turned on for testing. The results are as follows.

After powering on, it handshakes at 5V voltage, maintaining a power of about 15W for the first 59 minutes; then the power drops to around 9W and continues charging until 1 hour and 27 minutes; thereafter, the power continuously drops until the phone is fully charged, with the entire charging process taking about 2 hours and 23 minutes.

Plotting the data as a line chart shows that the Raspberry Pi 15W adapter takes 45 minutes to charge the iPhone 15 to 50%, 1 hour and 16 minutes to charge to 80%, and approximately 2 hours and 23 minutes to charge to 100%.

Standby Power Consumption Testing

Whether the charger wastes electricity when plugged into the socket but not in use is a question many readers have. The standby power consumption phase is designed to answer this question. The charger is plugged into the Beich power meter socket, and the power meter data is read to obtain the following results.

According to the power meter test, the charger has a no-load power consumption of 0.044W at 220V 50Hz voltage, which translates to an annual power loss of about 0.385KW·h. If the electricity price is 0.6 yuan/KW·h, the annual electricity cost of the charger is about 0.23 yuan.

Next, let’s take a look at the no-load power consumption at 110V 60Hz voltage. The power meter reads a power consumption of 0.028W, translating to an annual power loss of about 0.245KW·h. If the electricity price is 0.6 yuan/KW·h, the annual electricity cost of the charger is about 0.15 yuan.

Summary

Based on the no-load power consumption test above, the Raspberry Pi 15W adapter consumes about 0.23 yuan in electricity costs when plugged into a socket at 220V 50Hz voltage over a year; while at 110V 60Hz voltage, it consumes about 0.15 yuan when plugged into a socket over a year.

Conversion Efficiency Testing

The charger is essentially a conversion device, and there will be losses during the process, dissipated as heat. The power drawn from the socket by the charger is often greater than the rated power of the charger. The Raspberry Pi 15W adapter was tested for conversion efficiency under 220V 50Hz and 110V 60Hz AC input, and the results are shown in the figure below.

First, let’s look at the conversion efficiency at 110V 60Hz voltage for the 5.1V3A level, which is 84.48%.

Next, let’s look at the conversion efficiency at 220V 50Hz voltage for the 5.1V3A level, which is 85.71%.

Overall, the Raspberry Pi 15W adapter’s conversion efficiency is at a mainstream level among similar chargers under both voltage categories.

Ripple Testing

Since the charger uses a switch power supply, the secondary output of the transformer is not direct current, and it needs to be rectified and filtered through capacitors, meaning that there will be ripple in the charger’s output. Charger Head Network uses an oscilloscope to test the ripple value of the charger’s output, comparing it with industry standards to assess the output quality of the charger. The lower the ripple, the higher the output quality of the charger.

No-load Ripple Testing

First, let’s look at the no-load ripple performance at 110V 60Hz voltage. The peak-to-peak ripple value at 5V0A is 44mVp-p.

Next, let’s look at the no-load ripple at 220V 50Hz voltage. The peak-to-peak ripple value at 5V0A is 40mVp-p.

Load Ripple Testing

First, let’s look at the load ripple performance at 110V 60Hz voltage. The peak-to-peak ripple value at 5.1V3A is 48mVp-p.

Next, let’s look at the load ripple at 220V 50Hz voltage. The peak-to-peak ripple value at 5.1V3A is 42mVp-p.

Summary

According to the YD/T 1591-2009 communication industry standard, the ripple requirement for chargers is no more than 200mVp-p. The Raspberry Pi 15W adapter’s output ripple peak-to-peak value is no more than 48mVp-p under both 220V 50Hz and 110V 60Hz input voltages, overall showing good performance.

Temperature Testing

The charger is a conversion device, and there will be losses during the charging process, dissipated as heat, causing the charger to heat up. The Raspberry Pi 15W adapter is placed in a 25℃ constant temperature chamber, and the temperature of the charger surface is collected after one hour under a 5.1V3A load.

First, let’s see how the charger performs at 220V 50Hz voltage output.

After one hour, the maximum temperature of the charger surface, as captured by an infrared camera, is 61.7℃.

Using an infrared camera, the maximum temperature of the other side of the charger surface is 61.1℃.

Now, let’s see how the charger performs at 110V 60Hz voltage output.

After one hour, the maximum temperature of the charger surface, as captured by an infrared camera, is 64.5℃.

Using an infrared camera, the maximum temperature of the other side of the charger surface is 64.6℃.

Summarizing the temperature data into a table, the highest temperature under 220V 50Hz voltage is 61.7℃, and under 110V 60Hz voltage, the highest temperature is 64.6℃. For a 15W non-GaN charger, this temperature performance is relatively average.

Plotting the data as a bar chart shows that the maximum temperature of the Raspberry Pi 15W adapter under 220V 50Hz and 110V 60Hz voltage output is 64.6℃, meeting the requirements of the IEC International Electrotechnical Commission IEC62368 and the new national standard GB4943.1 2022 for electronic and electrical equipment testing, which states that the temperature should not exceed 77℃.

Charger Head Network Summary

The Raspberry Pi 15W power adapter features a simple pure white appearance design, with an integrated Type-C charging cable. In terms of charging tests, the charger supports a maximum output of 15W, charging mainstream mobile phones, tablets, and laptops with stable charging power. However, for devices with strict charging specifications, such as handheld consoles and laptops, it may lead to charging failure.

In terms of performance testing, the charger has a no-load power consumption of about 0.044W, which can be ignored; its output conversion efficiency is around 85% (line end test), which is at a mainstream level. Additionally, the ripple values during load do not exceed 50mVp-p, indicating stable output. Finally, under a 25℃ environment with a 15W full load state, the maximum temperature of the charger is 64.6℃, providing greater peace of mind during use.

Overall, the Raspberry Pi 15W power adapter has an integrated USB Type-C cable design and can charge devices such as the iPhone 15 series and mainstream Android phones and tablets. However, it is recommended to pair it with low-power devices that require continuous power supply, ensuring an unobstructed charging experience for users.

Leave a Comment Cancel reply