Solar Controllers--Don't be a Sucker! :(
Just got to say it again, how it is we are sitting here for five months off grid on solar with no problems at all (third season on solar like this), using the non-programmable, non-MPPT, solar control...
Forum Discussion
I don't quite understand the rant either. I'm not sure why some folks are so adverse to MPPT. I think it is quite a lot like years ago when automatic transmissions first came out. Let me say that I can't join the argument for or against MPPT with 12-volt panels as I have no firsthand experience with that and have seen the argument raging both ways.
In my case, the roof had very specific areas where solar panels could be placed without shading from other equipment. The only panel I could find that fit with the amount of watts needed were 24-volt. They were also cheaper than 12-volt of the same wattage.
A nice thing about 24-volt panels and a "proper" controller is that one doesn't have to worry about the afternoon when battery voltage has risen and panel voltage is declining. The MPPT is still producing the greater of either the actual amount the panels are producing or whatever the batteries will accept in addition to directly powering usage above what the batteries need. When the last glimmer of sunshine is disappearing and the controller is about to go to sleep, I have never seen the panel voltage less than 27 volts with about 500 mA going into the batteries.
On my last trip, the weather was nice and the battery bank was full everyday by midafternoon or earlier. The lowest the bank got was 85%. I don't expect that the weather will always be that cooperative and a few days of cloudy weather will drag the bank down much further. When that happens I want the controller to be able to put the maximum available into the batteries. I can say that I don't regret for one moment the little extra spent for the Rogue controller. I still think $1000 for a 370-watt system is not a bad price.
In my case, the roof had very specific areas where solar panels could be placed without shading from other equipment. The only panel I could find that fit with the amount of watts needed were 24-volt. They were also cheaper than 12-volt of the same wattage.
A nice thing about 24-volt panels and a "proper" controller is that one doesn't have to worry about the afternoon when battery voltage has risen and panel voltage is declining. The MPPT is still producing the greater of either the actual amount the panels are producing or whatever the batteries will accept in addition to directly powering usage above what the batteries need. When the last glimmer of sunshine is disappearing and the controller is about to go to sleep, I have never seen the panel voltage less than 27 volts with about 500 mA going into the batteries.
On my last trip, the weather was nice and the battery bank was full everyday by midafternoon or earlier. The lowest the bank got was 85%. I don't expect that the weather will always be that cooperative and a few days of cloudy weather will drag the bank down much further. When that happens I want the controller to be able to put the maximum available into the batteries. I can say that I don't regret for one moment the little extra spent for the Rogue controller. I still think $1000 for a 370-watt system is not a bad price.
