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Hi Dave, <br><br>
At 10:44 AM 3/26/2010, you wrote:<br>
<blockquote type=cite class=cite cite="">Is the answer here (at least the
one that NABCEP intends) just that the VMP of a "12V module" is
higher than the voltage of a 12V battery? With the higher voltage it will
charge the battery with its corresponding current based on the I-V curve.
The objective reads "Explain why PV modules make excellent battery
chargers based on their I-V characteristics</blockquote><br><br>
This may be the answer they want. The "Objectives" deals
with the 5 key points on the IV curve, Vmp, Imp, Voc, Isc and Pmp.
>From a study of the curve, the obvious "excellent" load is one
that takes power from Pmp, which direct battery charging doesn't
do. When I draw the curve, the Vmp of the module is above the
resulting voltage on the curve. <br><br>
What you say about the power loss not being released as heat in the
batteries, just not produced, makes sense to me. I've never
seen any real documentation about what happens to the power not gained in
a non MPPT battery charging system. <br><br>
We can definitely agree that "excellent battery charger" is an
exaggeration. <br><br>
Thanks,<br><br>
Drake <br><br>
<x-sigsep><p></x-sigsep>
<font color="#0000FF">Drake Chamberlin<br>
Athens Electric<br>
OH License 44810<br>
CO License 3773<br>
NABCEP </font><font size=1 color="#0000FF">TM
</font><font color="#0000FF">Certified PV Installer <br>
Office - 740-448-7328<br>
Mobile - 740-856-9648 </font></body>
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