24 volt controller uses

[Oneleggedcowboy]

• Gmorning, I want a very simple inexpensive solar system to pump water. Very light usage but for future expandable needs I want a 24 volt system. I have a 24 volt 245 panel on my slide in camper with a Eco Worthy MPPT controllet and it works great but the conttoller cost $100.  I would prefer to use another 24 volt 245 watt panel with a $15 dollar PWM conttoller. Got several panels for free from a friend. Can I use a 24 volt panel with a PWM conttoller that auto switches 12 to 24 volt with a 12 volt battery?  It will be on the high desert of Az. Out in nowhere and I need only a led light and a few gallons of water pumped. I have used a diaphragm 12 volt pump in my horse trailer with a cheesy Harbor Freight jump start battery pack for years with no issues but I want to leave a stationary system at my permanent horse camp. Thanks and please dumb down the reply. Thanks, Bill

 

[blars]

Instead of the normal 5% to 30% wasted power of using an 18v panel on a 12v battery, you'll have 53% to 70% wasted power using a 36v panel on a 12v battery, assuming the higher voltage doesn't blow out your PWM controller.

 

[jimindenver]

I use to know of a PWM controller that would dump that much voltage/ hence amps but it was as much as the ECO-Worthy MPPT.

 

[Oneleggedcowboy]

Hey Jim have you seen the Tracer controller on ebay that says it MPPT? There is one that is 10A for $54 That would be half of a Eco Worthy but I wonder if it's gonna work?

 

[jimindenver]

I use to pick my Eco-worthys up for less buy getting them in auction on ebay.

 

[jimindenver]

Hey Jim have you seen the Tracer controller on ebay that says it MPPT?  There is one that is 10A for $54 That would be half of a Eco Worthy but I wonder if it's gonna work?

It's not big enough. The panel is good for  at least 15 amps give or take.

 

[Oneleggedcowboy]

Thanx Jim and Techno Viking. We are now needing a MPPT controller. That's ok and now I can move forward with my purchases.

 

[Oneleggedcowboy]

Gmornin it's a bright warm morning in Eastern Carolina today!!!    I think I have figured out a good solution to my shed light and water tank pump in Az. 

I like the big 24 volt panels and my Eco Worthy 20 amp MPPT in the camper. So I wanted a 24 volt panel in Az. but with a cheap PWM conttoller and $55 Walmart marine group 24 battery. Yall convinced me I shouldn't put a cheap PWM on a 24 volt panel. I wanted to be able to upgrade the system to MPPT later for a cabin build.

I found a 100 watt complete system with  brackets,  cables, bolts, and a 30 amp PWM controller for $124 free shipping brand new on Amazon! This will do it just fine I think for bare bones basic. 

Then when I am ready to upgrade can't I do some kind of fancy stuff where I wire two 100 watt panels together to make a 24 volt panel set to hook to a MPPT controller???

 

[jimindenver]

yes you can