Usb charging of sat nav

Can I use the USB cable from car radio USB port to sat nav in order to
charge a Navman 20 whilst using it? The car does not have a cigarette
lighter socket.

Bobby

Yes. They are just 5V same as the USB port on a computer.

Yes, if it is powered. Some USB sockets aren't. Suck it and see!

What USB socket is not powered? An unpowered USB port would be useless and
commonly known as a 'hole'.
All USB devices plugged in to a car stereo require 5v to make them work,
thumb drives, card readers ...

Angus wrote:

Many devices that have self contained power do not draw power from USB
sockets, they only use the two data contacts to exchange data. Some
PDAs are that way.

And then there are the devices that would draw in excess of the USB
supplied maximum of 500 mA. Those will have a separate input for their
own power source, like an AC/DC adapter. As an example, some printers
and scanners are that way.

But you're right about devices that expect to get and need it, if there
were no power they would not work.

Then there are devices that have USB cables with "personalities", like
some of the nuvi's have. If those are plugged into a USB port, the
personality puts them into a certain mode. Like the nuvis that go into
a USB connected mode when a Garmin cable is used be act like GPS
receivers when a non-Garmin cable us used.

Jack