Fast charging of two devices simultaneously Power Bank 20000mAh Redmi has two USB ports for charging two devices at the same time. This, together with Quick Charge technology, ensures fast charging of connected devices. Quick Charge function The power bank can be half charged within 3 hours. During a quick charge it will adjust the output current to the connected devices to recharge it as soon a possible. The maximum output current is 3.6A. Low current charging for small devices Dual press of the battery check button activates a low-current charging mode for 2 hours, easy to charge small devices such as cordless headphones or sport watches. Fast two-way recharging 18W Supports up to 18W of input power via Micro-USB or USB Type C port. Supports up to 18W output power for a single USB-A port. Safe to carry on the plane Conforming to international aviation standards, safe to carry on the plane. 4 ports in Power Bank Xiaomi Redmi USB-C and Micro USB port for input, one more choice for charging the power bank 2 USB-A ports for output, charging 2 devices simultaneously Built with safety in mind Multiple protection for safety, e.g. overload protection, high temperature protection, short circuit protection.