Set it and forget it?

[menalice]

I am in the process of installing a PV system on our motorhome. 
We will be using 3ea 215w panels
A Combiner box on the roof
A Big Baby box in the Motorhome
MidNite Classic 150 Charge Controller
2000w Pure Sine wave Inverter
Three 12v batteries.

What I had envisioned was a system that can be set up, and with exception of checking battery fluid and an occasional cleaning of the panels, forget it. 
Is this a fantasy?

[Halfcrazy]

No I don't think it is a fantasy at all. There is always some maintenance but the bulk of that as you noted is the battery. Now that said you will always want to check on the status of the system and see if it is operating as intended. This can usually be as simple as checking the battery voltage here or there on a daily basis if you will

Ryan

[Westbranch]

What are your loads going to be?  2000W of loads on a 12volt system is pushing the limits of efficiency a fair bit, not that it won't work but anything over 1000W of loads should be evaluated against a 24 volt setup. 24v will use smaller wire and if designed well would have better performance all round.

hth

[vtmaps]

I would suggest a battery monitor.  Midnite makes a fairly simple one that will alert you if the batteries have not been fully charged for a few days. 

There are some more full featured monitors on the market, and Midnite is in the process of upgrading their monitoring... They have just released a shunt sensor (whizBangJr).  This lets the Classic know exactly what is going into or out of the battery.  With some additional programming the classic will at some point be able to tell you the battery state of charge.

--vtMaps

[Hialtitude]

What are your loads going to be?  2000W of loads on a 12volt system is pushing the limits of efficiency a fair bit, not that it won't work but anything over 1000W of loads should be evaluated against a 24 volt setup. 24v will use smaller wire and if designed well would have better performance all round.

hth

Hi, I'm also working to learn and build a similar system.    I understand that you can use smaller wire with a 24 v system.   But how would I evaluate the loads vs, 24v , also what would some of the considerations be for designing it for better performance? 

If I built a 24 system (say using 6 Golf Cart Batteries in series), what would be the best method to provide 12vs to the 12v circuits?  Would I just take 12 volts off of two of the 6V batteries, or use a 24V to 12V converter? 
 
I realize these are  noob questions and if there's an article or book chapter that you can recommend, I can check that out. 

thank you for your time. GP.

[menalice]

What are your loads going to be?  2000W of loads on a 12volt system is pushing the limits of efficiency a fair bit, not that it won't work but anything over 1000W of loads should be evaluated against a 24 volt setup. 24v will use smaller wire and if designed well would have better performance all round.

hth

First, thanks to all for the responses.  Obviously most of you are considerably more advanced in knowledge of the PV systems than I have actually ever hoped to be.  I go forth with much caution - attempting to not join the "one smoking box at a time" group - LOL.

Our heaviest load will be our Microwave - the 2000w inverter, like most of the rest of the system is over sized and leaves room for expansion.  The batteries are the exception to the rule - the coach came with two 12v "house batteries" but not the quality of battery I would choose if buying all new.  I took one, also new, from my boat (because I have it) and added it to help increase the storage capacity - all are new and all are about 170ah rating so I figure I will use them until they require replacement and then upgrade to a better (possibly 24v) system.  Having three 12v batteries, I stuck with the 12v system.

In my design, I included the six circuit combiner box on the roof to allow for the addition of two more (that would be using all of the roof area available) of the 215w panels, if they are ever required.

Again, I am in the process of installation and I am sure to return to this site for assistance in setting up the MidNite 150 when it's
actually time to flip the switch (and pray that it doesn't smoke!).

Thanks again!

[vtmaps]

Hi, I'm also working to learn and build a similar system.    I understand that you can use smaller wire with a 24 v system.   But how would I evaluate the loads vs, 24v , also what would some of the considerations be for designing it for better performance? 

If I built a 24 system (say using 6 Golf Cart Batteries in series), what would be the best method to provide 12vs to the 12v circuits?  Would I just take 12 volts off of two of the 6V batteries, or use a 24V to 12V converter? 

Welcome to the forum,
You have asked a few good questions... please start your own thread, it will be less confusing (to me, at least).  If someone else doesn't beat me to it I will be happy to answer your questions.  --vtMaps