DOI: 10.34808/srvh-ns18
title: Measurements of radiation emission of a portable power bank with a capacity of 5200 mAh

description: The dataset contains the emission measurement results that are part of comprehensive tests carried out for portable power banks with different capacities. The measurements were performed in the frequency range from 30 MHz to 3 GHz using a Gigahertz Transverse Electromagnetic (GTEM) cell. The test setup was configured to measure a portable power bank for various modes of operation. The data represents emission test results for a portable power bank with a capacity of 5200 mAh, consisted of rechargeable lithium-ion batteries installed in a protective cover, guided by a printed circuit board with DC-DC converter based on pulse frequency modulation technology. The basic parameters of the examined power bank are input and output rating of DC 5V, 1000 mA, mini USB input port, and single USB output port.
Radiated emissions measurements of electrical and electronic devices are carried out under the requirements set out in the standards of electromagnetic compatibility (EMC). The standard environment for emission measurements in the frequency range from 30 MHz to 3 GHz is the OATS (Open Area Test Site). A GTEM cell is an alternative measurement method, which allows evaluating the radiated EMC interference emitted from small electrical and electronic equipment. The results of the measurements carried out in the GTEM cell are the basis for the estimation of an equivalent OATS field strength.
The comprehensive tests were performed for different cases in charge and discharge mode, respectively (Fig. 1). In a discharging condition, the power bank was connected to an 8-bit AVR microcontroller or a typical smartphone. The power bank was coupled to a USB power adapter by a shielded USB cable of 80 cm in length. During working with loads, the power bank was connected to a microcontroller and a smartphone by a shielded USB cable of a length equal to 80 cm and 30 cm respectively. The emission test was also performed when the power bank was in standby mode for two cases; with and without a USB cable.
The measurement results reported undesirable effects related to the power bank’s operation. It was shown that the higher intensity of the electric field strength was caused by the tested power bank as well as devices connected to it. Tests proved that the examined power bank is characterized by the undesired EMC properties in standby mode with the USB cable connected as well.
The attached dataset contains files described as follows: EMI Report_capacity_mode of operation.Mode of operation:
standby mode, without the USB cable,
discharge mode
2_1. a power bank connected to the Atmel ATmega328/P microcontroller,
2_2. a power bank connected to the smartphone Samsung J3,
charge mode, a power bank connected to an AC mains outside or inside of the GTEM cell ,
standby mode, with the USB cable
4_1. a long cable,
4_2. a short cable,
4_3 a different arrangement of a long cable.
Additionally, a file EMI Report_surroundings.pdf containing the results of the measurements carried out with the GTEM door open without the power bank was attached.
EMI Report includes a hardware setup, EMI Auto Test Template, a spectrum of the radiated emission of the power bank in the OATS and on the GTEM cell’s output, and the final results of spectral components of the emission spectrum.  Figure 1. Block diagram of a test operation modes, charging (a), discharging (b) and standby (c), respectively.