Ive got a smartsolar 100/20 yet to be installed. This is going into my caravan and am loking to get 2 house panels to mount flat on roof. Using the victron excel spreadsheet when i input 2 x190w panels in series or parallel it comes up warning of over 30% overpowered. Originally was looking for 2 x170w panels in series but 190s seem easier to get. Would using 180s be a problem?
Look at VOC for the panel.
String VOC must be under 100V for that charger. Leave some safety margin for cold temperatures, when the voltage can be higher.
Also, usually 60 cell panels have best prices per Watt.
your smartsolar 100/20 is limited in solar voltage. Its maximum input voltage is 100V DC.
So if you put two panels in series, you have to check that 2xVoc < 100V (Voc is the open circuit voltage of your panel, see the datasheet of your panel).
And as seb71 says, "Leave some safety margin for cold temperatures" because when the temperature decreases, the solar voltage increases.
These panela are 44.5v voc. Coldest temp here would be 4 degrees Celsius
To calculate the temperature-corrected Voc, the panel temperature coefficient V temp must be known [%/°C]
But for 4°C the Voc don't increase a lot, so if you have only two panels in serie is is OK for this smartsolar.
As for the power of your smartsolar, it can produce a maximum current of 20A.
Now if it is connected to a 12V battery system it gives a max. power of 12*20=240W max.
For a 24V system => 24*20=480W max.
As you want to use two 180W panels, they should be able to produce 360W.But this is impossible because you are visibly using 12V system, and in this case the maximum power converted by this smartsolar is only 240W.
