If it can power a cigar lighter, it can power a sat nav, a lot of newer cars are not fitted with a cigar lighter, they are fitted with a power outlet which is not capable of powering a lighter safely due to thinner wiring.

Interesting.

On my car the wiring to the cigar lighter socket is very thin, whereas the wiring to the accessory socket in the armrest is very thick and has a relay:shrug:

I must admit I thought it was simple case that the cigar lighter socket was only for the cigar lighter, and that the accessory socket was for powering all other devices etc.

Although the OP's question was it OK to use a sat nav in the cigar lighter socket without problems and it seems the answer is yes..... so perhaps the beefy wiring to the armrest socket is for devices that need more power:shrug:

Maybe Im getting confused in my old age, I will stand corrected. Sorry.:getmecoat:

The theory is that the circuit for the cigar lighter is designed to only power the lighter for a few seconds and it is not on long enough to cause any problems. If a similar, or higher load was in continous use, it could overload the circuit. A satnav system has a much lower power demand and won't cause problems.

The circuit for the accessory socket is 'beefier' and designed to continously supply power.

Agree to a point, but don't want to go to the ins and outs of ...
http://www.sengpielaudio.com/FormulaOhm01.gif

From the cigarette lighter I run a gang of 3 (splitter)
1. Sat Nav
2. On board loop Camera
3. Fuzzbuster

All with no problems :D

None of which will cause problems with the cigar lighter circuit as they will not exceed the continous rating of the circuit - 1.5mm cable and a 15 amp fuse.

An example of a circuit rated for intermittent use is the starter motor circuit, you (should) only use the motor for a short time to start the engine.

If the engine does not start and the motor is kept turning, the cable can overheat and ultimately the insulation could be damaged, causing problems.

The size of the cable is accounted for in the design of the circuit as it is for intermittent use - to run continously, a much heavier cable would be needed.

No problem with my socket with satnav and tablet on charge on duel adapter even when I travel up to 300 miles here in NZ and that's none stop.

The problem I had was that my charger was so long that it got in the way of my automatic gearshift when in Park.

I had seen somewhere on the forum that someone had found a very short charger that you could operate, with trailing wire, and sill manage to close the lighter flap. I found something that looked right at Maplin, with a USB output socket, but unfortunately mine still couldn't be shut with the wire in place.

Worse was to come. Whilst driving to a friend who had recently moved house one day using GPS, my phone died despite signalling that it was charging. Somehow the amount of power needed for GPS exceeded the charger's ability to deliver that amount of power. So I had to drive the journey "blind", hoping that the phone would at least charge up enough to come on near my destination since it also contained a text message with the friend's address. Unfortunately the charger charged so little that even after an hour of charging my phone whilst switched off, it hadn't charged it enough to power the phone on, making it somewhat difficult to check the text containing their address!

So if anyone has recommendations for a decent, short charger, preferably with two USB type outputs, and even better one that the flap can shut behind with the cables present, please let mne know!

I had a similar problem once. I was using my phone satnav, and the gps was using up the power quicker than the charger could charge my phone. It was alright for journeys of less than an hour.
I don't have that problem now as I have a dd unit:}

Yes, USB Charging is of a much lower rate than the conventional charger that goes straight from your 'phone to the charging plug!