There are ports on the ReVIVE PowerUP DC labeled "A" and "B"

The ReVIVE PowerUP DC has two USB ports, "A" power and "B" power.

The "A" port will provide up to 2 amps of charging power and will charge devices needing 2 amps or less to charge, while the "B" port will provide up to 2.1 amps of charging power and will charge devices that need at least 2.1 amps to charge.

Some larger devices such as tablets require more power flow when charging, if the device to be charged does not accept a charge in the "A" port, please try it in the "B" port.