page_title: USB hardware
section_title: Sleep-and-charge ports
hierarchical_section_title: USB hardware / Power / Sleep-and-charge ports
caption_attribution_description: English: The yellow always on/sleep and charge USB port on the right side of a Thinkpad X220 laptop.
context_page_description: The initial versions of the USB standard specified connectors that were easy to use and that would have acceptable life spans; revisions of the standard added smaller connectors useful for compact portable devices. Higher-speed development of the USB standard gave rise to another family of connectors to permit additional data paths. All versions of USB specify cable properties; version 3.X cables include additional data paths. The USB standard included power supply to peripheral devices; modern versions of the standard extend the power delivery limits for battery charging and devices requiring up to 100 watts. USB has been selected as the standard charging format for many mobile phones, reducing the proliferation of proprietary chargers.
context_section_description: Sleep-and-charge USB ports can be used to charge electronic devices even when the computer that hosts the ports is switched off. Normally, when a computer is powered off the USB ports are powered down. This feature has also been implemented on some laptop docking stations allowing device charging even when no laptop is present. On laptops, charging devices from the USB port when it is not being powered from AC drains the laptop battery; most laptops have a facility to stop charging if their own battery charge level gets too low.
  Sleep-and-charge USB ports may be found colored differently than regular ports, typically red or yellow. On Dell and Toshiba laptops, the port is marked with the standard USB symbol with an added lightning bolt or battery icon on the right side. Dell calls this feature PowerShare, and it needs to be enabled in the BIOS. Toshiba calls it USB Sleep-and-Charge. On Acer Inc. and Packard Bell laptops, sleep-and-charge USB ports are marked with a non-standard symbol (the letters USB over a drawing of a battery); the feature is called Power-off USB. Lenovo calls this feature Always On USB.
caption: A yellow USB port denoting sleep-and-charge
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