A Gentleman of Noble Character
USB Charging Adapters from a Technical Support perspective - Insights

USB Charging Adapters have improved over the last decade. Yet, it's still prudent to verify the manufacturer's claims concerning the USB charger's published output parameters. Therefore, I have researched the numbers and recorded actual measurements from some common types of USB Charging Adapters and USB Charging Ports.


Most Hotels, Conference Centers, Boardrooms, Airports and Aircraft provide the standard 5 Volts DC @ 0.5 Amps public USB charging ports for your portable devices on their property and facilities.

Standard USB Data Hubs DO NOT provide FAST Charging. Only several hundred DC milliamps (150-300mA) are available for battery charging via these data hubs. For fast battery charging, use only USB Charging Adapters and Ports.

Charging your Smartphone directly from your computer's (or Laptop) USB ports will be a SLOW charge. These ports only supply about 5 Volts DC @ 0.3 Amps (or a just a few hundred milliamps). A USB Hub with its own external power supply MAY provide a faster charge.

Fast/Quick/Adaptive charges all must be supported by your portable device. Otherwise, the standard 5 Volts DC @ 0.5 Amps will apply.

ONLY connector pins 1 and 4 are used for charging. No standard USB serial data transfer is possible through a charge ONLY USB port. Pins 2 & 3 for USB Data transfer are either disabled or not connected.