Consumers of mobile devices expect manufacturers to produce devices that will be an efficient source of electric energy. The batteries currently used in smartphones allow the devices to operate for several hours. Power banks extend the operating time of the device without the need to charge via a charger connected to the mains. The present paper defines first the features of power banks that are the most important for users and, moreover, what knowledge or opinions about important power bank features customers use during purchase. As shown in the survey, according to the respondents, the most important feature determining the quality of a power bank is its capacity. It has been shown in this research that the actual capacity of a power bank is circa 2/3 of the capacity indicated. What have also been investigated are the differences between the average capacities of power banks with Li-ion batteries and the technologically newer Li-Po batteries, in favor of the latter. Power banks were not differentiated according to the type of battery and charging times in the standard variant, with a voltage of 5 V. It has been shown that the smaller usable capacity of the power bank does not affect the faster charging time.
This is an open access article distributed under the Creative Commons Attribution License
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.