wrote in message
...
On Mon, 21 Apr 2008 09:27:12 -0400, "Ed"
wrote:



A friend, who is an engineer, informed me that I am wasting my time. He
says
I need 12Volts from the solar panel to charge a 12 volt battery. Thus
the
7.2V will not do it.



Who's right, the manufacturer or my friend?


Neither. You need over 13 volts at a minimum to charge a 12 volt
battery.
100
milliamps isn't going to do squat, either. Also be aware that solar
panels
are
rated under ideal conditions, and you will likely NEVER see anything
close
to
the rated output. The panel you describe will actually DRAIN the
battery.


All of the small trickle charger solar panels (from decent companys) have
a
blocking diode that won't allow the panel to drain the battery.

All? Really? Are you sure? Is that safe to assume? Do you have a list
of these "decent" companies? Are there companies that are decent but
are not on your list? Are there companies on your list that are
otherwise decent but sell one or two panles that do not have a
blocking diode?

The specific company the original poster mentioned does NOT state that
their small panels have a blocking diode. Hmmm. They also state that
the small panels will not CHARGE a depleted battery.

:')

Any panel without a charge controller or a blocking diode WILL drain a

battery when the sun goes down so that makes it worthless.



A list of decent comps? No, but if you buy from West or another reputable
dealer you can return them if they prove to not have a diode.