Hi, this might be a classic beginner question.
In the Victron MPPT calculator if I select 4 panels 410w (Voc/V 44,8V and Isc/A 11,36) the suggestion is the MPPT 250/60 but if I select 5 panels the suggestion is a way bigger and more expensive hybrid device. Why doesn't the 250/60 or /70 or /85 not support 5 panels like that? Did I by any chance miss out on something important? Thanks for any comment!
Best, Ronny
The Voc will rise at lower temperatures. The Voc is at 25°C.
Depending on the panel the Voc will rise about 0,30-0,40% for each degree below 25°C.
In Winter your panels are cold, let's say 0°C than the Voc is 25 x 0,35% = 12,25% higher.
With a normal Voc of 44,8V + 12,25% you end up at 50,3Voc x 5 = more than 250V.
Since you say that you are a beginner:
Just in case you are not aware, you can make for instance two strings of 4 panels each (4 panels in series) and put those two strings in parallel.
So you can't have 5 of those PV panels in series on that MPPT, but you can have 8 PV panels (just not all 8 in series).
