These requirements cover power banks@ sometimes also known as portable USB chargers or portable back-up battery power@ which are standalone devices that incorporate batteries for mobile powering of low voltage electronic devices. These requirements cover products with the following power characteristics: a) Input: 1) Supplied by dc power source rated maximum 60 Vdc; or 2) Supplied by ac mains power source@ through direct plug-in construction. b) Output: Provides dc output(s) rated maximum 60 Vdc. These requirements do not cover products with dedicated inputs from external photovoltaic panels or vehicle 12 Vdc adapters@ or other power pack products under the scope of the Outline of Investigation for Portable Power Packs@ UL 2743. These requirements cover products with integral photovoltaic cells as power source.