Solar Charge Controller
Looking at solar and seeing different options for controllers. What's the difference between PWM and MPPT?
Forum Discussion
MEXICOWANDERER wrote:
I get dizzy re-reading these three pages.
What bubbles up to the surface is a couple of smaller batteries and hinges for the panels.
This is not MPPT territory, sorry.
MPPT is for higher voltage massive panels (but cheaper per watt), long runs of panel to controller wire and critical little bit extra charging at sunup and sundown. MPPT on a small system would be like a Goodyear Blue Streak racing tire on a wheelbarrow. Just my humble opinion.
Agreed.
And, having the ability to tilt the panels, especially as you go north and/or need solar in the winter, offers way more gain than an MPPT controller. A flat (horizontal) panel in northern states or fall winter captures way less solar energy than a panel reasonably tilted.
You can see a 25-50% or so increase in output current going from a flat panel to a reasonable tilt. Tilt should be approximately latitude + solar declination. Put a cardboard tube on the panel end on and adjust the panel for minimum shadow and check the current then lay the panel flat and see the difference.
Down where Mex is, probably not as big a deal, near the equator the panel wants to be near horizontal anyway. Where we are (Oregon) panels want to be around 45-60 degrees. Even in the southern U.S. you'd probably want a 30-45 degree tilt depending on time of year.
