Using two solar panels together

JumbleDuck

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I need to replace the solar panel on my hatch garage, and there's room for another one on the coach roof. Can I simply wire two panels in parallel into the input of a suitably heft (10A, probably) charger? Do the panels have to be matched, or can I mix 'em up a bit?

If they have to be the same the best I can find so far is two 40W polycrystalline panels (£161) but if I can mix them I can get 40W + 50W polycrystalline or perhaps even 40W poly + 60W mono for a broadly similar price.
 

Kelpie

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Interesting question. I would have thought that the diodes fitted to each panel would make a parallel install perfectly OK.
 

srm

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I have a matched pair plus another of similar size in parallel feeding in to an mppt controller, works fine from most sun directions even with one or more panel in partial or full shade.
 

noelex

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If parallel connected with non MPPT controller the only requirement is that both panels are (nominally) 12v panels (typically Voc about 22v and Vmp about 18v)

If you have a MPPT controller the panels should have a similar Vmp (usually within 0.5v is deemed acceptable, but closer is better) and ideally should have similar illumination.

With two controllers there are no limits.
 

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