powering a Satnav

[PaulSmith]

I am getting a satnav (Nuvi 2547LM) for the bike for an upcoming trip to France and I am looking for opinions on the best way to power it.

The options I can think of are to fit a lighter socket
http://www.ebay.ie/itm/New-12V-Car-Motorcycle-Cigarette-Lighter-Socket-Outlet-Lighter-Holder-Waterproof-/330939096068?pt=UK_Motorcycle_Parts_13&hash=item4d0d81dc04
or a usb converter
http://www.ebay.ie/itm/3M-DC-8-22V-12V-to-5V-3A-Mini-USB-Car-Supply-Power-Converter-Module-Regulator-/221225608043?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item338212e36b

but both have me worried about weather. The socket is weather proof if nothing is plugged in, but not when it is running the satnav, and the usb adaptor is only weather proof when it is plugged in to the satnav.

Virtual pints for the best ideas.

[cbx63]

You'd be better off with a Hella type socket , less chance of the plug vibrating loose

http://www.ebay.co.uk/itm/12V-DIN-Hella-type-Accessory-Socket-with-1-2m-Loom-Power-Kit-G-/290628515594?pt=UK_Motorcycle_Parts_13&hash=item43aacf370a

and a hella usb plug
http://www.ebay.co.uk/itm/Motorcycle-DIN-Hella-BMW-Style-Socket-Dual-USB-Charger-for-Phones-GPS-Satnav-/121044389723?pt=UK_MobilePhones_MobilePhoneAccessories_MobilePhoneChargers&hash=item1c2ececf5b

[ghostbiker]

I used to have a socket fitted in to the side infill. Worked fine never had an issue. Fitted direct to battery so I could use without keys in (fused)
When that infill broke in a drop I fitted a plug on top of the clocks between the clock and screen. Fixed with hot melt. This is much more protected from rain while riding.

[Ian-man]

I fitted a cigarette style socket on a fly lead from the battery and left it under the seat. I have a lead for my satnav tie wrapped from the handle bars to under the seat.
If I am using the satnav it just needs plugging in both ends. The socket is handy for a mini pump too.

[PaulSmith]

Thanks for the suggestions.
I take the point about the extra security from using Hella, but I think I can get the same security with an elastic band, and I can replace standard chargers at any petrol station, while Hella chargers are more expansive and more difficult to get. 

I am going to borrow Ian-man's idea and fit a 'standard' 12v Socket under the seat, and tie wrap a USB charger to the back of the clocks. I have a rubber USB cap that will protect that end when it is not in use.