I need some advice and information on this set up

Re: I need some advice and information on this set up

Leehamrick wrote: »

Hi,
Where I live we loose electric on a regular bases I just want to be able to charge up two deep cycle batteries.
I'm Deep in the appellation mountains In West Virginia 7 miles from a black top road in the high altitudes. 3800 FT
I only need to run some 12volt SMD/SMT lights and a small 12volt water pump that came out of a camper.
This is what I have to work with--(I got all this at one time from a guy that lost interest)
Solar Panel,, This is what it says on the back,,
Max power 235w
Max power voltage 29.44
Max power current 8.02 A
Open circuit voltage 37.21

For a converter I have a PWM the sheet that came with it reads,,
12 volt 24 volt
Rated solar input 20/30A 20/30A
Rated load 20/30A 20/30A
load disconnect 11.1V 22.2V
Equalization voltage 14.6V 29.2V <30 min
Boost voltage 14.4V 28.8V <30 min
Float voltage 13.6V 27.2V

For batteries I have two 12 volt deep cycle batteries that are for a boat trolling motor. 114 amp hours @ 1A

I have been told this is a 12 volt panel
And I have been told that the PWM controller is not a good set up for this panel and that
I should go with a MPPT controller.
I was told that the PWM will cut the amps way down----<true?
If this is true what model MPPT should I get? <--- I'm on budget but I will get what is necessary how many amp controller?
Can I wire my two batteries in parallel?

I know this is advanced solar forum but please keep it basic if possible <---be gentle I'm new at this

Welcome to wherever we are at the moment. :-)
Your set of questions, like your current knowledge, is pretty basic, and you would get just as good or identical answers if you posted your questions in the basic off-grid forums instead.
Since you have power some of the time, your goal to have a system that delivers backup power for specific limited purposes when the grid power fails will allow you to get a decent life from your batteries without the major expense of a full off grid system. And at the same time the small amount of power you have available from your panel means that you do not want to even look at a grid tie system right now.

You could also put together a reasonable system without solar, using an AC charger for your batteries, if you are only looking at an outage lasting a few days. That way you would not have to spend even more money for an MPPT charge controller (see below.)

1. You do not have a nominal 12 volt panel, you have a nominal 24 volt panel. This can be used reasonably efficiently with a PWM controller to charge a 24 volt battery bank.
2. But since you intend to drive 12 volt DC loads, you cannot just put your two 12 volt batteries in series to make a 24 volt bank.
3. Therefore, your PWM controller will produce a charging current of only 8 amps to your total of 228 AH of batteries (two in parallel). This is not really enough for a battery bank of that size and will only allow you to accumulate about 32AH on summer days and 16AH or less per day in the winter
4. A good MPPT controller, on the other hand, would give you 16 amps or more to charge your batteries.

You can make a useful start on your system and learn more practical information about it by starting with the PWM controller you already have. You may want to use only one of your two batteries in that case.
You will need to do things with fuses, battery health checking, etc. even for your basic system. You can find more information along those lines from sticky threads on the forum and will probably come up with questions after that.

Re: I need some advice and information on this set up

Leehamrick wrote: »

...
Max power 235w
Max power voltage 29.44
Max power current 8.02 A
Open circuit voltage 37.21
...

While these panels are more than 24V, they will have trouble topping off a 24v battery which would generally need
closer to 35V panels, to complete a charging cycle. And, since your loads are 12V loads, a 24V system makes little
sense at the moment. The existing PWM controller will work, but you will loose a fair amount of solar harvest with it,
and not be able to recharge BOTH batteries.

For a MPPT charger, you would want something at least 30 amps @ 12V. The
Rogue, Morningstar and Midnight offerings come to mind as candidates.
http://www.solar-electric.com/chco.html

Re: I need some advice and information on this set up

" Quote Originally Posted by inetdog View Post
Welcome to Solar Panel Talk."

vtmaps wrote: »

I find that a bit disorienting over here at wind-sun --vtMaps

Haha I noticed that too, and wondered where I was, what forum I was on - - - lol

Re: I need some advice and information on this set up

Cariboocoot wrote: »

Okay, from now on we'll just call it "Solarspeak".

Or Coot's playground! LOL

Re: I need some advice and information on this set up

i half expected you guys to come back with something like, you can't have a conversation with them when they are outside on the roof.

Re: I need some advice and information on this set up

niel wrote: »

odd, i've never heard any solar panels speak before.:p

I understand the Midnight controllers will speak.....