Can a laptop be powered and it's battery charged through only it's USB Port?

Question

Sorry to answer my own question but I found this on the patent database.

"A laptop computer and mating docking station where the docking station provides power to the laptop computer over power rails of the Universal Serial Bus (USB) interface. The laptop computer has laptop docking logic that both provides power in accordance with standard USB protocol, and also receiving power across the power rails of the USB interface. Likewise, the docking station has a docking station dock logic that establishes communication with the laptop docking logic across the USB power rails. Once positive communication is established, the dock station provides voltages on the USB power rails sufficient to power the laptop computer as well as charge the laptop's battery."

HP patented this idea but is it actually being used. This Dude at Dell says I can use a port replicator to charge my battery but even the people who make the port replicator disagree. And I've found no evidence to the contrary.

Answer 1

The original USB specification indicated a maximum of 500mA draw by a device on the USB port. This is the reason why external HDD with high power draw have dedicated power supply. Most USB ports not designed to interface with a docking station will not be able to handle the very high electric current of the whole laptop.
A typical laptop draws 65W. That could be up to 13,000mA on the USB power rail (5V) when laptop battery is in discharged state and being powered through a USB port.

Answer 2

It sounds possible, but only when using a docking station.

Not all laptops have docking stations, only certain models.

You would have to read the tech specs on each docking station model to find out for sure.

I found an interesting site about a different kind of docking station:
http://www.cnet.com.au/laptops/accessories/0,239035630,339281911,00.htm

Answer 3

USB is divided into 4 inner cables, 2 that pass records , and 2 for ability. in case you employ in basic terms the flexibility cables then you certainly can deliver electrical energy to a minimum of something which includes a battery. The cables are generally colored crimson, White, eco-friendly, Black crimson (+) is for sending ability (5V) Black (-) is the grounding modern eco-friendly and white are for sending and receiving records It get complicated previous that although, as oftentimes a USB port will transmit at maximum 5V, in case you like this to fee a battery or such, you may would desire to attach some transistors or resistors to tweak the ampage and wattage so which you do no longer blow the battery. and you apart from mght could evaluate the resistance of the wires. So in case you do your study wisely, a soldering gun and a visit to radio shack is all you will need. in case you have chose to fee a battery for a laptop like this, it is going to artwork, in spite of the undeniable fact that it is going to fee very sluggish.

Answer 4

No