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dram avatar image
dram asked

Victron MPPT SmartSolar 100/20

Hi guys, I'm thinking to add another panel to my 100/20 MPPT and I'm not certain how tight the MPPT's solar panel Isc tolerance is.

Currently, I have a single 335W half cut panel with a Voc - 41,5V and Isc - 10.73A.

Since I have some substantial shading during a specific time of the day, I'd like to connect the panels in parallel so as the shade transitions over the panels I can extract as much as possible till the array is fully in shade.

Can the 100/20 MPPT take 2x 335W solar panels with a combined Isc of 21,46A STC, thus higher in summer?

Thanks.

MPPT ControllersSolar Panel
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4 Answers
Alexandra avatar image
Alexandra answered ·

@DraM

20A is the limit. It is a hard limit.

It is also a limit that only matters when there is a mistake made such as reverse polarity [as noted in the tech spec sheet.... (2) A higher short circuit current may damage the solar charger in case of reverse polarity connection of the PV array.]

And in some instances where the mppt shorts out the input such as when it is trying to prevent overcharging.

So during normal running you can 'get away' with it. But it will sacrifice itself (with no warranty) if there is an issue.

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gazza avatar image
gazza answered ·

I stand corrected. I have indeed just checked the spec and input is also 20A max. Apologies!

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filterguy avatar image
filterguy answered ·

@DraM Why would a controller short circuit the input? It seems to me that it would be better to just turn off the current input in order to prevent overcharging.

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kevgermany avatar image kevgermany ♦♦ commented ·
It's the panels.
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kevgermany avatar image kevgermany ♦♦ kevgermany ♦♦ commented ·
Input current is always less than output as input is at a higher voltage under normal operation. Panel current can be exceeded if there are higher numbers in series, so should be fused if more than two in the string.
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astrayan avatar image
astrayan answered ·

If the specs say 50A, I go 40

If they say 150V, I go 120

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