Serious problem

[bruadair]

Excellent price for the 130s. We would have bought the 130s but three years or so ago they weren't offered yet, so we got the two 120 watt panels. I think we paid around $450 each for them and at the time I believe it was close to half of what we would have paid through WM. Hope you like them,

Damon
s/v Bruadair
The Adventures of s/v Bruadair

[bottleinamessage]

I've heard random comments that something called an MPPT (?) controller is a good thing to use. Anyone know what it is and why it (if it is) superior to an "ordinary" contoller?

[GordMay]

Maximum Power Point Tracking, frequently referred to as MPPT, is an electronic system that operates the Photovoltaic (PV) modules in a manner that allows the modules to produce all the power they are capable of.
Goto:
http://www.blueskyenergyinc.com/pdf/...0is%20MPPT.pdf
And:
OutBack Power Systems - MX60 MPPT Charge Controller

[camaraderie]

The short version of MPPT is that panels typically put our about 17.7 volts at their rated amperage in full sunlight.
Since batteries will take a charge at somewhere around 14.4V, a normal regulator will throttle back the 17.5 volts to the batteries from the solar panels converting it to heat instead and wasting avilable power.
MPPT controllers instead convert the excess voltage to amperage and give you more amphours per day into your battery as a result. Overall gains are typically in the 10-15% range on average.

[camaraderie]

The short version of MPPT is that panels typically put out about 17.5 volts at their rated amperage in full sunlight.
Since batteries will take a charge at somewhere around 14.4V max without damage, a normal regulator will throttle back the 17.5 volts to the batteries from the solar panels converting it to heat instead and wasting avilable power.
MPPT controllers instead convert the excess voltage to amperage and give you more amphours per day into your battery as a result. Overall gains are typically in the 10-15% range on average.