RW Salnick wrote:

RW Salnick inscribed in red ink for all to know:

KLC Lewis inscribed in red ink for all to know:

"Larry" wrote in message
...

"John" wrote in
:


The manufacturer claims an increase
in current power of 30%.



What nonsense. The controller turns the panels OFF at the appropriate
time. It doesn't manufacture power from thin air. I wouldn't buy his
product because he lied to me.



Larry
--
Democracy is when two wolves and a sheep vote on who's for dinner.
Liberty is when the sheep has his own gun.




IIRC, Practically A Sailor did a test and review on those units, and
verified the manufacturer's claims.



How do the Maximum Power Point controllers work?

bob
s/v Eolian
Seattle



OK, nobody's answering me - I'll try it myself...

IIUC, the "power Point' controllers are basically DC-DC converters,
converting the 19 volts or so that the panels produce to 12.6 (or
something), thus drawing from the panels at their output voltage instead
of the battery's voltage. Presuming minimal change in current delivery,
this would represent an increase in delivered power.

OK, where am I wrong here?

bob
s/v Eolian
Seattle
Assuming the panels can be modelled as an ideal voltage source with a
(variable) series resistor (they cant but its a useful approximation)
you are extracting the *maximum* power from the panel when its loaded to
half its open circuit voltage, BUT you are unavoidably wasting the
*same* amount of energy in heating up the panel. (n.b. this does *not*
work for getting maximum *energy* out of a battery). I suspect they
will actually be boosting 9.5V up to 12.6.

--
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