Author Topic: best way to wire 4 solar panels  (Read 2704 times)

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delboyo

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best way to wire 4 solar panels
« on: November 17, 2014, 02:01:54 PM »
hello to you all, I have a question please, I have 4 solar panels, 250w 24v 8.9a, the panels actually read 37.4a open circuit 30.1a maximum power, at present they are connected in series charging 4 110a 12v leisure batteries, the question is what is the best way to connect them here in UK where the sun don't shine much. I am very confused as there are a lot of websites giving me different configurations. I have solar charge controllers going up to 60a so that's no problem. At the moment all I am running off it is my fish pond and the lights in my shed, which are led, thanks all very much.   from delboyo.

Bruce S

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Re: best way to wire 4 solar panels
« Reply #1 on: November 17, 2014, 02:47:23 PM »
Welcome to the forum

That can be a loaded question  :D.
We'll actually need a bit more information to help.
The charge controller can be the main deciding factor for how the panels are conncted.
Is the charge controller a 12V , 24V or higher?
Since  panels are 24V, my best guess would be that the controller is 24V as well.
IF you currently have the panels in parallel , which gives you 24Vdc with a possible 32A charging max, I would leave them alone. YOU could go with a MPPT controller and get a better charging rate, but they can be $$$$ :(.
The other factor is the amount of current being used by ALL of the devices listed. Since you have 4  batteries , I would wire them up for 24Vdc which will give you 220A, then make sure your devices are not draining them down to less than 40% overnight or at a point where the sun can give back .
Hope that helps
Bruce S
A kind word often goes unsaid BUT never goes unheard

delboyo

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Re: best way to wire 4 solar panels
« Reply #2 on: November 23, 2014, 12:20:23 PM »
Hello Bruce, thanks for the reply, the controller I have at the moment is an MPPT 24v 380w 40a, the panels are connected in parallel at present. I have 3 24v pond pumps working 24/7 each taking about .3a so just under an amp an hour, led lights in the shed take 1.2a when they are on.  The question I would like to know is if the panels are connected for 48v 500w 17.8a would I get a better charging current. I am a bit lost with solar panels as I am 63 and only now getting the urge to produce something free (after the initial outlay).I have a 48v 1000w charge controller on the shelf I bought just in case. I intend getting more panels for the roof in the future if these work out in our rubbish weather. Derek.

tanner0441

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Re: best way to wire 4 solar panels
« Reply #3 on: November 23, 2014, 03:15:51 PM »
Hi

I am in the UK and looking for low voltage lamps etc I found there is a ruck of 24V stuff for trucks and buses. So I would stick with 24V. Having said that MPPT on 48 is more efficient, and if you were looking at grid tie or a 240V system from an inverter cable sizes would be smaller.

You will have to explain more about what you want to do and what your constant loading is going to be.

Brian

delboyo

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Re: best way to wire 4 solar panels
« Reply #4 on: November 25, 2014, 01:21:41 PM »
Thanks for that Brian, I think I will stick to 24v for now as what you said made a lot of sense, truck bits and pieces I did,nt think of that one. I will be looking at a grid tie system around 4kw,a mate bought one on e-bay for £2500, £1000 for fitting and he,s sorted. I might go down that route,at least it will save me something. thanks for replying, Derek.

tanner0441

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Re: best way to wire 4 solar panels
« Reply #5 on: November 25, 2014, 04:27:45 PM »
Hi

Don't forget if your going for grid tie then the installation need to be carried out by an approved installer. So they might dictate the voltage you use...

Brian.