Subject: Re: goin' mobile with solar

From: Jim Devenport <[email-masked]>
Date: 19 Sep 1995 20:57:25 GMT

I had a Ford van that I lived in on remote work 
assignments, not for 2 months at a time without outside 
energy & food input, hee, but it worked well and was very 
simple:
I just installed a 37 Watt older crystalline photovoltaic 
panel on the roof.  I used 18 guage standard AC "cheap 
extension cord quality" zip cord to run it to the existing 
auto battery, and after a while installed a diode in series 
with the positive lead to the battery to prevent the panel 
drawing a few milliamps at night when not exposed to light.
I did not have any real heavy power consumers, but ran the 
following with no problems:
Cheap mail-order 12 Volt flourescent light (15 watts or so) 
for reading
Small Black & White TV set
Commodore 64 Computer and monitor
12 Volt Soldering Station for electronic tinkering
FM stereo & tape deck with a used "Ghetto Blaster" boom box 
I bought for $20 at a flea market
12 Volt DC fan to keep me air cooled during hot weather
Various amateur "ham" radio transceivers

All the above was intermittent usage.  Using no extra 
batteries you have to monitor your battery voltage and keep 
>from  running it below 11 volts.  I found little trouble as 
I drove the vehicle enough to keep the battery alive in 
spite of often drawing more than the 3 amps available from 
the solar panel.  With a panel that size even if I did run 
my battery down "in the middle of nowhere" with a day or 2 
of good sunshine I'd have enough "juice" to get the engine 
started again.
Nice-to-have enhancements if affordable:
Automatic voltage monitor that disconnects the battery when 
the voltage falls below 11 or so volts (with deep cycle 
batteries the voltage can drop maybe a volt lower without 
longterm battery damage).
Extra battery compartment with deep cycle batteries and a 
relay that allows the 12 volt "accessories" to run off the 
deep cycle battery without draining the vehicle main 
starting battery
             3 Amp 100 PIV diode
-------|  +         |
Solar  |------------>|------To Vehicle battery +
Panel  |
       |  -
       |--------------------To Vehicle battery -
-------|

Cheers,
-- 
*********** Jim Devenport WB5AOX **************
*      PO Box 445, McIntosh NM 87032          *
*        http://nis-www.lanl.gov/~jdport/     *
***********************************************