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.