On 01/07/2013 21:38, 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.

Yup, that's mostly type.

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?

The satnav will likely have a resistive touch screen. These have a
slightly soft feel to them and require a small amount of positive
pressure to activate. They are older technology, but quite well suited
to things that you primarily want to prod at on screen buttons.

Modern higher end phones will have capacity touch screen. These just
feel like hard glass, and are far more sensitive - they respond to
sliding touches and "swipes" better and can usually recognise multiple
points of contact simultaneously, allowing recognition of multi finger
gestures.

Makers of smart phones have worked very hard to get longer battery life.
For satnavs its nice, but less essential since they are most often used
where there is power available. Older satnavs were often better due to
being physically larger and allowing for larger batteries. However as
the prices have fallen they have got smaller and cheaper in construction
as well as price. My old tomtom go 700 can still do 4 to 5 hours on
battery, and that has a (small) spinning hard drive in it. My phone
could probably manage similar life - but 5 hours would take a sizeable
chuck of its battery capacity (although its a physically very small
phone and only has a 950mAh battery). The battery monitor on the phone
is quite sophisticated and will tell you which activities are using the
power. The display is the number one user. However enabling GPS uses a
bit. Wifi uses quite a lot, bluetooth a little bit. Cellular data a fair
bit (depending on signal levels).


--
Cheers,

John.

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