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christianf avatar image
christianf asked

MPPT: limits and exceeding of PV input voltage

Hi all,

even after reading through https://www.victronenergy.com/blog/2014/03/28/matching-victron-energy-solar-modules-to-the-new-mppt-charge-regulators/ and several posts here, I couldn't find an answer to my question:

Given there are two 200WP solar panels with Voc=46,6V and Vmpp=40V, connected in serial to a Smartsolar 100/30. Online MPPT calc says; it's a match. As long as you don't enter the temperature coeffients, which I'm trying to obtain since some days now by contacting manufacturer, searching online etc.

When playing around with values of -0,25% to -0,35%, the calculator jumps between Smartsolar 100/30 and 150/35.

Question: how hard is the voltage input limit really? What happens if it is exceeded by 0,1V or 1V or even 3V? Is there a tolerancy? Will it kill the MPPT or will it just shut off and be back again at normal voltage?

Thank you
Christian

MPPT Controllersvoltageovervoltage
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2 Answers
kevgermany avatar image
kevgermany answered ·

Hard limit. Will kill the MPPT.

You'll get away with a little, but best to play safe with the 150 or connect in parallel if you have a 12 or 24V battery

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over-and-under-victron avatar image over-and-under-victron commented ·
I'm curious....what is a little when exceeding voltage? One percent?
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kevgermany avatar image kevgermany ♦♦ over-and-under-victron commented ·

Zero, it's down to component tolerances. Always design for safety.

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Alexandra avatar image Alexandra ♦ over-and-under-victron commented ·
A little, meaning once or twice with temperature and cloud edge effect. But continuous over no.

Datasheets for all panel manufactures should give the co efficient. Or the sticker on the back.

But normally a 46v VOC you go higher in practice for voltage rating on the MPPT.


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peter-3 avatar image
peter-3 answered ·

46v for 200 watt panels ? , My 300 watt panel are only 34.1v @ 11.8a , so sound like your panel are high voltage low current , so can go parallel ? .

But that depends on what voltage of the battery 12v or 24v

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klim8skeptic avatar image klim8skeptic ♦ commented ·
It's all about the number of cells in series.

A higher number of cells equals a higher Vmp / Voc.

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MPPT Product Page

MPPT Error codes

MPPT 150/60 up to 250/70 Manual

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