David Nebenzahl wrote:

On 2/26/2009 1:13 PM Pete C. spake thus:

David Nebenzahl wrote:

Told a guy I'd do some research for him into a small simple solar system
for use in maintaining the charge on a 12 volt automotive battery. Found
this at Harbor Freight:

http://www.harborfreight.com/cpi/cta...emnumber=96418

It's a 12 volt, 15 watt panel for cheap ($70).

The 45W three panel package that Harbor Freight sells for ~$200 is the
best value $/W and the panels are decent. You have to replace the junk
charge controller they provide with a decent unit though.

Any suggestions? I'm not familiar with these units (charge controllers),
could use a little guidance here.

45W = 3.75A or so so you don't need a big one.

http://shop4.frys.com/product/498009...H:MAIN_RSLT_PG

Sunforce 60012 7 amp Charge Controller

Solar:
FRYS.com #: 4980091

or

http://shop4.frys.com/product/563300...H:MAIN_RSLT_PG

ICP CC-10000 10Amp Battery Charge Controller

ICP:
FRYS.com #: 5633001

Would do the job. I got the later one, I think it's a bit nicer. Either
one gives some headroom to add a few more panels.

Fancier MPPT controllers will give the best efficiency, but the extra
cost probably isn't worthwhile for a tiny array.

The HF kit also comes with a couple decent little 12V CFL lights which
can be handy and a basic rack for the panels.

http://www.harborfreight.com/cpi/cta...emnumber=90599

The HF stores usually stock the panel kit, and if you sign up for the
flyers and emails you can often get a 20% off coupon for the stores.

Good resources here as well: http://www.homepower.com/sample/

Look through the sample issue where you will find plenty of vendors. The
electronic edition subscription (download pdf) is a decent value.