With a growing number of USB devices in my car, and wanting a few of those to be powered at all times, or to be switched on when the car is on, I built a new module. The main reason was for my GPS tracking phone with Mologogo (boost I455, stays in the car, on all the time), and powering my Samsung A900 when I'm in the car using it for data transfer via bluetooth, cuz it sucks some serious juice doing broadband speeds.
Anyways, hooked them up and things have been gravvvyyy
The module supplies 1.5A of power, USB specs are 500mA per port, so this should do fine.
It has a DIP switch to set the powering setup, either Always On, or On With Vehicle.
Just wire up the constant +12vdc, switched +12vdc and ground (and USB cable to CarPC and your devices).
Great for those higher powered devices, charging cell phones, ipods, external dvd/cdrom drives, external hard drives, etc.
Each module supplies up to 1.5A (1500mA).
The module has one USB port, with data pass-through, the module supplied USB power is isolated from the CarPC.
The power and usb cables are 3 feet each.
Has a wide input voltage range and is designed specifically for powering peripheral devices used in an automotive environment.