solar panel wiring

andy63 said:
Andy is the load terminal not supplied by the batteries...
I know on another mppt type of controller that the load terminals can be timed and provide lighting etc even though the solar panel is not producing (ie at night )..so that has to be supplied by the battery bank..
I haven't checked the controller that's been discussed here just assumed it would be the same...
Andy
Click to expand...
Yes supplied by the battery or solar. The battery gets the net charge if higher than the load.
Obviously it can not measure what is being taken directly from the batteries away from the load terminals
 
rogher said:
But, if it's showing 13.2V and 3.5A, should that not be 46W?
Click to expand...
when i took the picture i did see the wattage go up and down , and i am sure that the wattage in the pic was at max just as i took the picture
 
Bart said:
@Sheddy Thanks for the comparison :) . whats the most that you have seen your panel at with the 3 x 100W panels ?
Click to expand...
An early July reading
CA_07051412505728-L.jpg
 
My panels will have been generating power since February 2013 :xThumb: so four years next February
SILENTLY
solar.jpg

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now i'm looking forward to the free power as well :D
 
My guess is that if you want to really see what the panels will produce on a given day, you need to put a reasonable load on the batteries first. If the batteries are fully charged, or nearly so, the controller will be turning itself down to prevent over charging.
 
Curiously, all of the displays above show "0W" output.
So is the current (below) a function of the input W and the battery V, rather than the actual current flowing into the battery?
 
There is nothing connected to the load terminals so why do you expect a load reading
 
TheCaller said:
My guess is that if you want to really see what the panels will produce on a given day, you need to put a reasonable load on the batteries first. If the batteries are fully charged, or nearly so, the controller will be turning itself down to prevent over charging.
Click to expand...
Guess ill have to make myself another coffee then from the inverter :D :D

rogher said:
Curiously, all of the displays above show "0W" output.
So is the current (below) a function of the input W and the battery V, rather than the actual current flowing into the battery?
Click to expand...
I know all my outgoing load is displayed in my sterling monitor as it all goes via the Shunt

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Yes, try placing a major load on the tab battery and see what happens to the "0W" and compare that figure with what your Sterling monitor says.
Is there not a user manual that explains what each part of the solar controller's display is supposed to represent?
 
Yes and I told you already
Unless you connect a load to the load terminals it will show 0
 
I think what Andy is trying to say is that if you have nothing connected to the "load" terminal which are marked with a "light bulb" in his photo above (and not connected), then you will show 0watts in the top right, you can flatten your batteries as much as you like but it still won't register anything other than 0W.

Martin
 
What sort of items do people attach to their "load" side of the controller ?
I'm just curious :)
 
Bart said:
What sort of items do people attach to their "load" side of the controller ?
I'm just curious :)
Click to expand...
A pair of 12v cigar sockets (fused of course) to power the router for the wifi and 12v water pump if needed.
Cheers
Ed
(The max I've seen on my system is over 200w but I don't keep going out to the garage to check it, if the sun is shining I'm generally otherwise occupied with a can in my hand)

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Last edited:
Bart said:
the sun was out , even if it was down low.
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Do not underestimate the angle. Try this.

Draw a horizontal line on a sheet of paper.
Take a ruler or even a bread knife.
Put it at 90 deg to that line ( your roof ). Draw either side. That width is your solar panel, getting full sun ( never happens in UK ).

Now angle the ruler at 45 deg get on edge on the edge of the "solar" and draw again.
Put ruler at 60 deg, repeat.

That ruler represents a shaft of sunlight, notice on 45,60 the shaft well overlaps the solar, at 60 deg you will see only half of the shaft hits the panel, you have a 50W panel at that angle. You can see that if you raise the panel to be square with the sun the increase is quite dramatic here up north.
 
Bart said:
What sort of items do people attach to their "load" side of the controller ?
I'm just curious :)
Click to expand...
Nothing, mostly. In a motorhome, all the loads are already connected to the existing 12v distribution system.
It can be a convenient place to pick up an extra 12v supply if you are adding something else. Whether this is a good idea or not often depends on the existing 12v control system - often it pays to route everything through the original control panel.

Depending on the controller, you may be able to set parameters as to when power will be supplied to the load terminals. They are supplying battery power, rather than direct power from the panel only. So they usually have low voltage protection, to switch off before the battery goes dangerously flat. Some have a timer function, to power lighting systems. They can be set to switch on when the input from the solar panels falls off (i.e. dusk), then either switch off at dawn, or a certain number of hours after midnight, or some similar parameter.
 
Techno said:
Yes and I told you already
Unless you connect a load to the load terminals it will show 0
Click to expand...
Ah, now I've got it!
I assume that the original design was for the only batteries to be connected to the central position and the rest be connected to the 'load' side. Probably OK until you add an inverter, when the wires would not be thick enough.
 
Bart said:
What sort of items do people attach to their "load" side of the controller ?
I'm just curious :)
Click to expand...
You can connect something to the load side and then even when the control panel is switched off the load will remain live unless the batteries go flat and then the controller should be set to cut the load.

Remember this type of controller is not limited to Motorhomes, it might be on a boat and you want to keep some running lights on at night, or a camera security system on a boat or motorhome.

Martin

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