Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 09, 2025 ...

So, to try to understand this, if you see 26 amps at your controller, and if you get that for 4 hours a day of bright sun, are you then sending (up to) 104 amps total to the battery in that 4 hour period?  Do I have it right?

John, sent you a PM.  Thank you!

Screwing something into the roof is my next fear to worry about.

I think I get the electric calculations of it all. 

Next step is to ask why I'd want to spend $610 on a controller, when it seems that I could get one for less than $200 with enough capacity to handle what I decide to put up there.  I do not really care about the infinite amount of metrics that some controllers would display for me, as I think all I really want to know is told to me by the Trimetric I have (and the Prosine readouts).  At this point in my life, I don't want a lot of extra data to think about; I have too many other challenges.  BUT, on the other side, I do not want to spend too little if something isn't really going to work and last and that is why it is cheaper.

To dumb it down in the simplest terms I am thinking about:  Starting out with a full battery bank (2 x 225A), if I have a lot of electricity use going on and it's cloudy outside with the Trimetric showing a falling battery voltage, I know what's gonna happen.  It will be generator time sooner rather than later.  But if it's sunny outside and the Trimetric shows 13 volts and no negative flow out of the batteries, then I know I can turn another appliance on if I need or want to do so while it is still sunny outside. 

Starting out with NO solar, anything will be an improvement on reducing generator time.  I realize it is NOT really cost-efficient, but it would be nice to get a bit of quiet power added to the batteries, especially being headquartered in Arizona where finding sun isn't a problem.  Maybe after the apocalypse, I'll wish I had 2kw up there.

You could start with a much less expensive Chinese controller that would handle one or two smaller panels and then add another later. Nothing wrong with two controllers on one set of batteries.

Pierce

I thought Uni Solar went bankrupt.
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Quote from: Bill Willett – March 02, 2014, 06:01:22 pm

I thought Uni Solar went bankrupt.

True, but the panels are still availablen and at sale prices. All you lose is a warranty.

Have you checked this out with the controller manufacturer or in real life? It might be true with old tech linear analog charhe controllers, but today's pwm and mccp controllers migght have voltage spikes getting in each othervs way. I see the possibility of the feedback systems going completely haywire.

I think I get the electric calculations of it all. 

Next step is to ask why I'd want to spend $610 on a controller, when it seems that I could get one for less than $200 with enough capacity to handle what I decide to put up there.  I do not really care about the infinite amount of metrics that some controllers would display for me, as I think all I really want to know is told to me by the Trimetric I have (and the Prosine readouts).

Controllers are not all equal. You get the most of the available solar energy conversion from an MPPT controller. They are more efficient, versatile and "kinder" to your batteries. Research early on saves many $$$$ later. Don;t ask me how I know.


Roland

author=Roland Begin link=topic=20460.msg150768#msg150768 date=1393815638

Controllers are not all equal. You get the most of the available solar energy conversion from an MPPT controller. They are more efficient, versatile and "kinder" to your batteries. Research early on saves many $$$$ later. Don;t ask me how I know.


Roland

Would expensive batteries, photovoltaic arrays, and their associated equipment really last long enough to pay for themselves before they go bad? Even with diesel at $4 per gallon I can run my genset for several years of battery charging for that kind of money... just saying... always the voice of the cheapskate on here

Would expensive batteries, photovoltaic arrays, and their associated equipment really last long enough to pay for themselves before they go bad? Even with diesel at $4 per gallon I can run my genset for several years of battery charging for that kind of money... just saying... always the voice of the cheapskate on here

I understand.  The smartest among us are usually the ones who have already made the most mistakes.  I do understand the value of the MPPT controllers, but even they seem to vary wildly in price for the same amperage capability.  I'll keep accumulating info!

Would expensive batteries, photovoltaic arrays, and their associated equipment really last long enough to pay for themselves before they go bad? Even with diesel at $4 per gallon I can run my genset for several years of battery charging for that kind of money... just saying... always the voice of the cheapskate on here

Would expensive batteries, photovoltaic arrays, and their associated equipment really last long enough to pay for themselves before they go bad? Even with diesel at $4 per gallon I can run my genset for several years of battery charging for that kind of money... just saying... always the voice of the cheapskate on here