outback solar mppt controller
anyone had any experience with the outback mppt controllers? I see solar blvd has a 10A for $99 and a 20A for $149. the 20 A would be a nice update from the morningstar 15A at a reasonable price...
Forum Discussion
BFL13 wrote:
About $125,--- here is an example of a PWM gone way overboard for "features" IMO. I am guessing the guys who invent these things get carried away with what is possible, never mind the poor RVer who just wants to get some sunshine on his panel to get the battery up some. Following the setting up instructions in the manual would drive me crazy.
http://www.midnitesolar.com/pdfs/10-293-1_REV-D_bratManual.pdf
In this case it makes the PWM more expensive than the Eco-Worthy MPPT.
Good point. Though, a bit of apples to oranges here :)... This Midnite is 30A. Eco is 20A. Features like remote temp comp are often necessary, and at high current a remote voltage sensing may also become necessary. Some other features of this model are just "bells", Christmas lights, I agree.
Poor Rver is an interesting angle. If they are in for something longer than a weekend, then financially it would make the most sense getting a system as big as possible, to avoid the use of generator as much as possible. This normally results in 24V panels and MPPT, space permitting.
OTH, if the purpose is getting "some" juice off the sunshine, i.e. solar as an auxiliary energy source when opportunity presents, and the panel is small - then one can get away with the simplest and cheapest controller. Proper charging algorithm or setpoints won't matter then, it's a temporary fix anyway.
More amps from 12V panel with MPPT... How much more and how often? 120W flat panel would harvest 40AH at best. With MPPT it will be what - 42AH? This is, if it's not too hot.
I never tried small single 12V panel. Wouldn't have much use for it in my situation - it would be like driving a car with one gallon tank. So, correct me if I'm wrong. You need 14V after controller. Panel can do 17V under perfect conditions. So there is 3V for conversion. If conditions are not perfect, you're getting less than 17V and have very little, if anything, for MPPT conversion. Ops - current the same as with PWM. Or less. Then it warms up and PWM wins. This is just one of possible scenarios. The point is - 20% gain expected by the OP with 12V panel (compared to PWM) is unrealistic.
