For a huge output and for devices to quickly power up, this RAVPower 20,000mAh Dual Port Power Bank lets you enjoy a combined 5V/3.4A output that meets the needs of smartphones and tablets. Each of the two iSmart ports provides the optimized charging experience for your device while allowing 5V/2.4A output per port. When using a 2A or 2.4A adapter, this power bank recharges in a speedy 9 to 10 hours. That means you are saving at least 50% on the recharge time compared to using slower 1A adapters. To make things convenient and to minimize tangled wires, all three USB ports are grouped together for easy access. This power bank is also packed with four charging safeguards so you can power up your device with the utmost protection.