powering a tomtom xl live from in car usb socket

searchlight123

basically my proposed new car only has a 12v cigarette lighter socket in the ashtray area which has to be open to access the socket. i want to run a tomtom sat nav with power lead hidden as much as possible.
the best power outlet for this is from a usb socket inside the centre armrest.

is this outlet ok to power the tomtom from as opposed to the more usual cigarette lighter style outlet? the car in question is a new 3 series bmw if that makes any difference. i guess i'm asking if someone could check for me who has a usb output in their car (bmw) whether they're lead that connects their tomtom to their pc / laptop will also supply charge / power to the tomtom in the car also?

many thanks.

Astronaughtwannabe

Yes, not a problem. I used to run mine on the cars USB.

Iceweasel

There should be no problem whatsoever using the USB outlet for power.

The cable length could be a problem though.

In my 3 series I use a cigarette lighter / USB adapter in the ashtray socket which means that the sat-nav can be plugged in there and the ashtray lid shut.

searchlight123

many thanks for the replies. that good news. my present 3 series has a cigarette lighter type socket in the centre armrest that allows the sat nav to be plugged in and the armrest cover closed. the new car i'm getting only has a 3.5mm aux outlet and a usb socket within the armrest.

someone told me that they thought the in-car usb would be only for data output and may not output the 5v power needed to run / charge the satnav? so many thanks for confirming this arrangement will work.

as for the cable length, i have seen the correct leads needed on ebay in 2 or 3 metre lengths, so that part should not be an issue.

Head_The_Ball

Be careful, that socket is not designed for powering external devices.

I have a Feb 2015 BMW Series 1. The handbook says this about the USB socket.

Connection for importing and exporting data.......

...Do not connect any devices such as fans or lights.

...Do not connect up USB hard drives.

...Do not use the USB audio interface for charging external devices.

I don't know what current that USB socket is capable of supplying but the handbook suggests that it isn't the usual 500 mA (USB2)or 900 mA (USB3).

I don't know why BMW appear to have fitted a USB socket that doesn't meet USB power specs.

I have not tried to use it for powering or recharging. Maybe it will work maybe it won't. Personally I wouldn't risk it in a new and expensive car when the handbook specifically tells you not to so do.

Ask your question on a BMW owners forum. I would be interested in the responses that you get.