Hello I have the victron 100/20 MPPT and plan to have 4 100W Renogy panels.
I live in south central Alaska with minimal sun in winter.
System is 12V Multiplus II 120V. Only have one 100AH Lifepo4 battery with plans for one more.
The panels will be two series strings and then paralleled.
Can this MPPT safely handle this configuration?
Thank you.
I tried the online linked mppt calculator and it recommended the 100/30.
Maybe I mistype something.
Your 100/20 maximum current output (into the battery or loads) is 20A.
When used in a 12V system (12V nominal battery voltage), this means it can output at most 12V x 20A = 240W (this is simplified, because the actual battery voltage will be higher than 12V most of the time, so the maximum power output is slightly larger - about 288W).
So this means it won't use the full power your panel array is theoretically capable of producing (400W).
A 100/30 would be able to do that.
But most likely your panels won't produce 400W anyway a lot of the time. During cloudy days you might only get 20W or 40W. So an oversized PV array (oversized within reason) is not wasted, because it gives you more power in poor weather conditions (when you need it the most).
Since you didn't bougth the 4 x 100W PV panels yet, I would recommend to reconsider this purchase and go for one 60-cell PV panel (around 300W) or one 72-cell PV panel (around 350W), if shipping for this in Alsaka is not much more expensive (since it is a larger panel).
