question

jura23 avatar image

Smart solar 100/30 + 330wp or 545wp

Hello,


I am building a van with a 12V system and I already have a smart solar mppt 100/30 built in.


I can get it from a friend for good money


https://hadex.cz/g968-fotovoltaicky-solar-panel-36v330w-polykrystalicky--*pozor-doprava*/


1x 330wp polycrystal 2x1m

Max. no-load voltage Voc = 45.71V

Max. short-circuit current Isc = 9.01A

Max. voltage at load 330W: Vmp = 38.45V

Max. Current at 330W: Imp = 8.59A


Then others told me to put it on the roof as much as possible. So I'm thinking maybe this one would get in there:


https://shop.iftech.cz/solarni-panely/3218-solarni-panel-munchen-solar-545wp-mono-stribrny-ram.html


1x 545 wp monocrystal 2,3x 1x15m

Max. no-load voltage Voc = 49.4V

Max. short-circuit current Isc = 13.9A

Max. voltage at load 545W: Vmp = 41.2V

Max. Current at 545W: Imp = 13.2 A


they say they will never go full power on the flat roof of a car.


the question is? Is it necessary to go to such a panel at all? would it stand it 100/30?


does it make sense or just 330wp is enough?

may a better choice be two smaller ones?


sorry for my english. Jiri

MPPT Controllersbattery chargingSolar Panel
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1 Answer
wkirby avatar image
wkirby answered ·

MPPT 100/30 can make ~444W on a 12V system. 14.8V x 30A = 444W.

545W module would be a very good choice. Like you say, maybe you will not see full PV power from a flat module, but a higher power module will be fine for the MPPT, it will limit at 30A. Also on cloudy days a higher power PV module will be better.

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Thank you for your response. I would still ask. If I opted for a larger panel, could the smartsolar be damaged if the sun did give over 500Wp?


Also, does it matter if one panel is used or two that have similar power in total? Is there a better assumption of function when overshadowing one of them?


Thank you very much :)