solar panels can you fit different sizes?

Submitted: Monday, Feb 01, 2010 at 19:25

ThreadID: 75680 Views:3419 Replies:2 FollowUps:12

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bushy04

Can I put a 65w and a 50w Solar panels in a parallel?
I don't have enough space to put another 65w but a 50w will fit.
I have an old 65w panel that works on its own but will not increase the amps when hooked in psrsllel, don't think that this panel has a blocking diode so the better panel is all that comes through to the regulator.
Trying to get all this up and working before we head of in June for three months.
Thanks in advance..
Bushy.

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Reply By: Peter_n_Margaret - Monday, Feb 01, 2010 at 20:00

Monday, Feb 01, 2010 at 20:00

Should be no problem.
I have 3 @ 80W + 2 @ 120W = 1 @ 125W in parallel.

Cheers,
Peter
OKA196 Motorhome

AnswerID: 402148

Follow Up By: bushy04 - Monday, Feb 01, 2010 at 21:22

Monday, Feb 01, 2010 at 21:22

Thanks , thats what I thought, but the amps in good conditions should be about 6amp plus but the most i've got has been 3.9amp.

Bushy.

FollowupID: 671609

Follow Up By: Member - Andrew (QLD) - Monday, Feb 01, 2010 at 22:23

Monday, Feb 01, 2010 at 22:23

Those numbers right Peter?

Andrew

FollowupID: 671624

Follow Up By: Peter_n_Margaret - Monday, Feb 01, 2010 at 23:10

Monday, Feb 01, 2010 at 23:10

I would have thought that is about right, in full sun conditions & not too hot.
Can you measure each panel seperately? Perhaps the 50 is not working?
What are the panel's individual specs? Do they have similar voltages?
What controller are you using? Is it OK at 6A?

Cheers,
Peter

FollowupID: 671635

Follow Up By: bushy04 - Tuesday, Feb 02, 2010 at 08:19

Tuesday, Feb 02, 2010 at 08:19

Peter n Margaret, am using a 20amp reg.
PV CHARGE CONTROLLER MP3129. It has a digital display which would appear to be accurate.
Thanks Bushy.

FollowupID: 671667

Follow Up By: Member - Andrew (QLD) - Tuesday, Feb 02, 2010 at 08:35

Tuesday, Feb 02, 2010 at 08:35

Thanks Peter, not having a go....just that i read it as you have 3 panels rated at 80W, and 2 panels rated at 120W, which gives 5 panels. I wouldn't have thought that this equates to just 1 panel at 125W. That's how i read your statement, which sounds like i might have read it incorrectly. ;)

Andrew

FollowupID: 671669

Follow Up By: Peter_n_Margaret - Tuesday, Feb 02, 2010 at 10:47

Tuesday, Feb 02, 2010 at 10:47

Sorry Andrew......typo...
Should read...I have 3 @ 80W + 2 @ 120W + 1 @ 125W all in parallel.... =605W.

Bushy, check the open circuit voltage of each panel seperately with a voltmeter, then connect each seperately to the regulator and see if that suggests any problem.

Cheers,
Peter
OKA196 Motorhome

FollowupID: 671690

Reply By: Maîneÿ . . .- Tuesday, Feb 02, 2010 at 00:44

Tuesday, Feb 02, 2010 at 00:44

"I have an old 65w panel that works on its own but *will not increase* the amps when hooked in parallel"

Then may I suggest it is wired up incorrectly, as it definately will increase the Amps when wired in parallel correctly, because as you say it works independantly.

Maîneÿ . . .

AnswerID: 402193

Follow Up By: bushy04 - Tuesday, Feb 02, 2010 at 08:14

Tuesday, Feb 02, 2010 at 08:14

Mainey both positives together on the same connecter, same on neg.
Would think that if one worked,then both should work?
Have been a fitter for 45 years so maybe senility is setting in.

Thanks Bushy.

FollowupID: 671666

Follow Up By: Maîneÿ . . .- Tuesday, Feb 02, 2010 at 10:52

Tuesday, Feb 02, 2010 at 10:52

Bushy,
"have an old 65w panel that works on its own but *will not increase* the amps when hooked in parallel"

If the panels work independantly then they will work in parallel.

In parallel circuit, each component has its own direct path to both the negative (-) and positive (+) sides of the circuit as shown in the simple schematic diagram of a parallel circuit below.

Image Could Not Be FoundMaîneÿ . . .

FollowupID: 671693

Follow Up By: bushy04 - Tuesday, Feb 02, 2010 at 17:22

Tuesday, Feb 02, 2010 at 17:22

Mainey ran the Engle all night then turned it of and hey presto, 5.4 w in full sunlight today,
so the old panel is working (just).

thanks for youre help Bushy.

FollowupID: 671770

Follow Up By: bushy04 - Tuesday, Feb 02, 2010 at 17:23

Tuesday, Feb 02, 2010 at 17:23

Mainey ran the Engle all night then turned it of and hey presto, 5.4 w in full sunlight today,
so the old panel is working (just).

thanks for youre help Bushy.

FollowupID: 671772