Voltaic Systems V15 4,000mAh USB Battery Backup Bank for iPhone, iPad, Samsung Galaxy, Android, and HTC Devices SOLAR OPTIMIZED - High quality, high temperature Li-Polymer cells tested and optimized for solar applications. CAPACITY - 4,000mAh / 15 watt hours provides 1.5 charges to smart phones, .65 charges to 7" tablets. Designed for use with Voltaic solar chargers, solar panels, and accessories. POWER OUTPUT / INPUT - 1 USB (5V 1.0A) output and 1 MicroUSB 5-6V 1A input. PACKAGE INCLUDES - The Voltaic 15 battery and 1 cable to charge MicroUSB devices from the battery. ALWAYS ON FEATURE - Voltaic's selectable "Always On" feature makes it easy and efficient to use with various sensor or time lapse applications (see below). Hold Power Button for 8seconds LED lights will blink 3 times and remain lit for a few seconds to confirm the mode is switched to Always On Hold Power Button for 8seconds LED lights will blink 3 times and immediately turn off to confirm mode is switch to Auto Off <span class="a-text-bold">Capacity</span>: 4,000mAh, 15 Watt hours <span class="a-text-bold">Output</span>: 5V/1A USB <span class="a-text-bold">Input</span>: 5-6V, 1A <span class="a-text-bold">DC Input</span>: MicroUSB <span class="a-text-bold">Battery Type</span>: Li-Polymer Short circuit, over charge, over discharge, over current, over temperature 4.0 x2.5 x0.5 inches 4.4 ounces