Date: Fri, 18 Mar 2005 10:16:07 -0700
Reply-To: jbrush@AROS.NET
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Anonymous Digest <jbrush@AROS.NET>
Subject: Re: Solar power
In-Reply-To: <20050318165031.68830.qmail@web21323.mail.yahoo.com>
In <20050318165031.68830.qmail@web21323.mail.yahoo.com>, on 03/18/05
at 08:50 AM, Barb Cotton <cottonscrafts@YAHOO.COM> said:
>I need some advice. I am getting an Optima battery installed to run my
>stuff when I am camped, and want to get a solar charger to keep the power
>up when I am parked. I am looking at 2 different ones in the Northern
>Tool and Equipment Catalog. One is small enuf to sit on the dash,
>maintains 12 volt car, truck, MC, boat, or RV batteries for $29.99. The
>other does all that plus says it is ideal for deep cycle, otherwise
>similiar to the cheaper one, for $69.99. Also quite a bit bigger. I don't
>want to spend more money than I have to, but want to get one that will
>work for me. Will the smaller one work, or should I get the bigger one??
Hi Barb,
The first question that really matters most is, what kind of 'stuff' are
you going to run. Solar power is expensive, so you want to understand how
much power you will be using, before you can choose the size of the solar
array you would like to use.
It all depends on what you want to accomplish, and how much you want to
spend. There is no blanket answer to your question, but IMO, the small
panels you are looking at will not be worth the cost and effort, as they
simply don't provide the current you need to replenish your battery.
Neither of them will even provide enough power to run a decent lamp for
four hours at night.
Its pretty easy to check over the items you want to power, and read the
amp or watt ratings for each device. Multiply times the hours you would
run them each day, and you come up with total amps used, or watts if you
prefer. Watts = Amps times 12 ( for a 12V battery) If the device is rated
at 3 amps, that is 36 watts. If it is rated at 24 watts, that is 2 amps.
(very rough numbers)
If your devices add up to 15 amps, and you want to use them for two hours
a day, you need a very large solar panel to replace all those amps.
Solar power costs between about $5 per watt, in larger panels, much more
in the smaller ones. Figure 10 watts per square foot. This really makes
them cost prohibitive for camping, generally speaking.
If I can help with ideas or figuring out your total usage requirements, I
would be happy to do so. Vans I know pretty okay, but solar stuff I get
along with, and can offer actual, useful advice on :-)
John
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