On Mon, 01 Jul 2013 21:38:01 +0100, The Medway Handyman wrote:

My sat nav battery only lasts about half an hour unless plugged into the
fag lighter socket. I was told that the display screen is what consumes
the power.

The sat nav has a touch screen, but you can touch it with anything - the
end of a pencil for example.

The smart phone (Samsung Galaxy Ace) can be used as a sat nav for hours
without appreciably draining the battery and also has a touch screen,
but you have to use a finger or special stylus - the end of a pencil
don't not work.

Can someone explain the differences in technology?

First question is which SatNav you have.

I have a TomTom (special deal for older stock) and the battery is hosed.

Already changed it once under warranty (just got another by return - they
didn't fix the battery).

I can buy a new 3rd party battery of t'Internet and there are instructions
for fitting it but it does involve some fairly scary levering off of glued
down bits to get the old out and the new in.

So I've never got to the point where the benefit of a new battery
outweighs the risk of screwing it up.

So the answer you didn't ask for may be to replace the battery to get more
life out of your current SatNav.

Cheers

Dave R

P.S. portable USB power pack might help mobile use as well.