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motorhomer avatar image
motorhomer asked

Max solar on MPPT 100/30 advice please

I have a Victron MPPT 100/30 which I will be using on a 24v system.

I know the max wattage is 880w and max OCV is 100v

I have a choice of two solar setups. 300w panels which will be max 900w and OCV in series 102v

or I can go with the 250w panels which means it will be within the MPPT settings but 150 watts less.

My question is, can I go with the 300w panels, will this damage the MPPT or will it just restrict output to the max output of the controller.

I expect being in the UK the panels will never reach the max output as these are ideal figures but just in case I get a really amazing sunny day :)

MPPT Controllers
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kevgermany answered ·

Wire the panels in parallel. Then plenty of headroom for voltage increases die to winter temperatures.

Check short circuit current, Isc of the panels is in within the specs of the controller remember they're in parallel, so double the single panel value.

Over sizing the panels is fine if you don't over do it, common practice in places that get little sun, or the sun is low in the sky. If you get to full panel output, the controller will limit the current without a problem.

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motorhomer answered ·

Wiring in parallel will be the same slightly over the controller max rating by 3A. i am thinking same as you, I very much doubt I will get full solar output to cause any issues and I assume if they did one day the controller will just limit the panels


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kevgermany avatar image kevgermany ♦♦ commented ·
It's not thinking on my part. It's documented that this is how the controllers work.

Parallel is to prevent the controller from overvoltage, not to limit current or panel output. The max voltage on the input side is exactly that. Do not exceed, ever.


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