question

westen avatar image
westen asked

Will 6x 160W panels (30V) in paralel hurt MPPT 100/20?

hello,

Last winter I installed some extra solarpanels to increase solar yield from an often absent sun. Now, with summer approaching, I wonder if I should disconnect some of the panels.

12v system here: 6x 160W solar panels (approximately 30V) connected in parallel to a 100/20 MPPT. It gets me through winter just fine. But I am afraid of frying the MPPT in summer... So should I disconnect some panels?

MPPT Controllers
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3 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

The maximum PV shot circuit current for the 100/20 is 20A .
You should not extend this value.

https://www.victronenergy.com/blog/2014/03/28/matching-victron-energy-solar-modules-to-the-new-mppt-charge-regulators/

btw the 100/20 can charge you batteries with a maximum current of 20A @ 14,4V (absorbtion voltage of a lead battery) you get 288W of charging power.
So you don't need more than 3 panels to get this.

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JohnC avatar image
JohnC answered ·

Hi @westen

I love 'overclocking' panels. But you have to do it properly to be safe. And your 6x parallel panels aren't, even in winter.

It's likely you'd be ok with 2x in series and 3x of those strings paralleled (2S3P). Run your exact panel figures through this calculator:

https://mppt.victronenergy.com/

If it recommends a mppt within the specs of yours, you'll be ok. For all seasons.

And you'll get good poor light performance and a longer productive day.

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westen avatar image
westen answered ·

Thanks Matthias and John, for your answers.

For starters I just disconnected 2 panels. Looking at the calculator I see I'll need to do more: either upgrade the MPPT or invest in a dc/dc converter.

I guess I'll go for the MPPT-upgrade.

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