External battery (power bank) – PURIDEA S15. It allows you to charge devices without access to a permanent power source. The product is available in several colors. Large battery capacity (10,000 mAh) allows you to fully charge a standard smartphone (a standard smartphone has a battery of approx. 2000-2500 mAh). Small size ensures comfort of use and facilitates storage of the product when not in use. Solid housing is durable and resistant to damage. Ports: Micro USB and USB C allow you to charge more than one device at a time. Specification: Capacity: 10,000 mAh / 3.7V (37Wh) Input (Micro USB): 5V-2A Input (USB C): 5V-2A Output (USB 1): 5V-2.1A Output (USB 2): 5V-2.1A NOTE! Nominal capacity expressed in mAh (milliampere hours) means the sum of all cells that were used in the power bank. The cells used have a voltage of 3.6 – 3.7V, while the standard USB port – 5V, so voltage conversion is necessary, which in turn translates into real capacity. After conversion, it is usually around 65-67% of the original value. This means that for a power bank with a capacity of 12,000 mAh, in fact about 8,000 mAh is available.