Rolf wrote:
Sorry this topic has been discussed in many forms before.
I need a computer for the boat which I am going to buy ( 45 to 50 ft
cruising sailboat). I initially considered a desktop but was scared
off by the power consumption.
Now I am considering a Laptop. I want to use it to run navigation and
other boat soft ware, but I also want to use it for e-mails and for
web surfing when I have access and also to watch DVD's and CD's, so I
feel I need a Pentium 4 with Windows XP.

The Pentium 4 is not noted for power economy, a better bet would be the
Pentium M Centrino, since you will eventually be able to use Wi-Fi on the
boat. It consumes much less power than the P4 and is just as fast/powerful.

There is a bewildering choice of brands. One way to narrow the choice
is again power consumption from the house batteries since the computer
will be on a lot.
I can get an inverter and then plug in the power supply to that. But
that route looses about 20% of the power.
The better option is to have a DC to DC converter like one that is
used to connect a Laptop to the cigarette lighter in a car. But how
much power does that consume?

A friend of mine has just blown up an IBM Thinkpad by using a DC-DC
converter. We think he was getting "spikes" from the alternator, which the
converter could not handle, whereas an inverter plus the laptop's own power
supply would have easily coped with the extra voltage. This was an expensive
mistake on my part as I recommended the converter!

Third choice, is there a brand of Laptop eg Toshiba or others which
accepts power stratight from the House battery, ie a voltage anywhere
between 10 and 15 volts?

Not unless you go back about 10 years. All the old laptops used to be
runnable from DC 12 Volts. The latest ones require 19 volts (some even use
20 volts). Forget this one.

Either go for a mini-PC with separate TFT panel, or a Centrino-powered
laptop from Tosh, (A60), Thinkpad, (R40)or Compaq, (M700) powered by an
inverter (300 watt min.), and the laptop's own PSU.


Dennis.
Remove "nospam" from return address.


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