Here is an extremely handy tool. a combination amp/volt/hz, and Watt meter.
As you can see from the photo, the meter plugs into a domestic socket and then you plug the device to be measured to the meter. We purchased this one from Amazon for bout US$25.00. And have learned so far that the MacBook Pro 17″ computer averages 30 Watts when on, compared to the Imac, with an extra 25″ monitor and two external 1.5tB drives which draws 200 Watts. Kill A Watt make a series of these of which this is the simplest. They are available with different plug styles.
Posted by Steve Dashew (May 27, 2010)
May 30th, 2010 at 10:47 am
Hi Steve,
Being careful with selecting your devices can be very interesting for yachties — even your generator powered FPBs can profit from this, as you have been finding out. If you don’t have a generator this becomes even more important.
I found that choosing your components wisely can shave a lot of Watts off your energy budget.
For instance:
Incandescent/Halogen vs LED lighting: 10W – 3W
32″ flat screen TV: 150W versus 60W
Computer: 100W – 40W – 20W – 12W – 4W (not all with the same capabilities, but still)
MFD (Chartplotter): 25W versus 10W
For instance, running a 10W chartplotter instead of a 25W one will mean 20 Ah @ 12V per day instead of 50 Ah @ 12V (half that with a 24V battery, of course) out of your battery. That’s pretty significant in my opinion as it saves you running your engine for hours per day. It might even mean meeting demand with alternative sources such as wind or solar.