In a message dated 16/06/2007 11:10:45 P.M. Eastern Standard Time,
LISTSERV@GERRY.VANAGON.COM writes:

Date:    Sat, 16 Jun 2007 19:57:31 -0700
From:   Michael Elliott <camping.elliott@GMAIL.COM>
Subject: Re: Solar  panels for your Vanagon..

Hi Don,

Right on. I can't tell if  generator people are oblivious, inconsiderate,
or some mixture of  both.

To others considering a solar rig, I would suggest using wire  thicker
than lamp cord to "remote" the panels. Low voltage systems are  high
current systems, so wire resistance wants to be low in order to get  as
much power from the panels to the battery. That means fat  wire.

Lamp cord is usually pretty skinny stuff, like 22 gauge. A  15-foot
length of 22 gauge has about .36 ohms of resistance (send and  return
combined). In my system, the panels might be delivering 4.7A @ 17  volts
in full sun. That's 80 watts. If I were using 15 feet of 22 gauge  wire,
the voltage lost due to wire resistance would be .36 x 4.7 = 1.7  volts.
At 4.7 amperes, that's 4.7 x 1.7 = 8 watts lost as heat in the wire,  a
10% loss.

Standard North American-style household grade ac  receptacles and plugs
are supposed to have less than .03 ohm contact  resistance -- when new.
That adds .06 ohm more resistance to the mix, with  an additional 1.3
watts of loss.

11% may or may not be important,  depending on your system. It's just
something to consider. I wanted the  freedom to locate my panels pretty
far from the van, in case the good  sunlight isn't conveniently close. I
use 6 gauge wire, and a 40-foot  extension. That's just .028 ohm, giving
a loss of .6 watts passive wire  loss. The PP75 Anderson Powerpole
connectors have only .0002 ohm of  resistance.

--
Mike "Rocket J Squirrel" Elliott
71 Type 2: the  Wonderbus
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74  Utility Trailer. Ladybug Trailer, Inc., San Juan  Capistrano
KG6RCR

Mike,  thanks for this GOOD advice.  This is information I had not previously
 thought about.  Where are you storing the 40' extension and how much space
is taking up ?  AND, why 40' why not 50' or 100' ?

Cheers,

Frank  Condelli
Almonte, Ontario, Canada
'87 Westy, '90 Carat, '87 Wolfsburg  (Forsale) & Lionel Trains (_Collection
for sale_ (http://members.aol.com/Fkc43/trainsal.htm) )
_Frank Condelli &  Associates_ (http://members.aol.com/Fkc43/busindex.html)
- Vanagon/Vanagon Westfalia Service in the Ottawa Valley
_Vanagon Stainless Steel Exhaust  Systems_
(http://members.aol.com/Fkc43/stebro.htm)
_BusFusion_ (http://members.aol.com/BusFusion/bfhome.htm)  a VW Camper
camping event, Almonte, ON, June 07 ~ 10,  2007