> So any suggestions for a regulator system
> 1) shuts off dc power to dc circuit panel when voltage is less than 12v
from
>     2nd battery
> 2) acts as regulator for a passive solar  charge
Well since the list died for a few daz :(
I did some R&D into the low volt cutoff, charge controllers
I truner over a number most a prices out of van camper prices points

The picture is not compelete but some things look just right
for the regulator/solar charge controller/metering this is looks realy great
Morningstar prostar 15M -$150 with lcd meter
http://www.morningstarcorp.com/products/ProStar/index.shtml

or if you realy want the optimal charge ctl the bluestar energy ppmt
controllers
but these are more for large installs
http://www.blueskyenergyinc.com/pdf/SB3024i_datasheet.pdf

dc circuit panel
and Bussfuse make a very nice 6/8 circuit spade fuse panel 15600-06-20 for
$20
http://www.bussmann.com/library/bifs/15600.PDF

any one else have other controller the like to point out?