Hi all
I am doing a new layout, using 3 21.2 voc 9 amp panels in series, the calculator says to use the 100/50 but I was thinking of the 100/30. Mostly because on a previous system I never saw more that 30 ish amps.
I am also considering the 150/35. And indeed a 100/50 which is I can source at same price as the 150/35.
For both the input potential of 585w to go to a 12v (really 13.8v lithium system) is higher than the potential output. I always believed this is ok, but the supplier of the 150/35 says it’s not and that the max input would be 500w.
I am also curious as to wether the 150/35 is a better/or newer design unit than the 100/30 or the other way round.
Thanks for any replies.
As long as the maximum input voltage on a cold day is below 100V (yes, about 70V) and the maximum input current on a warm day is below 35A (Yes, about 10A) the you can over panel the 100/30. Typically people use a rule of thumb of about 30% overpanelling being economic. So 30 x 13 x 1.3 = 507W, which matches your supplier statement, but the 30% is not a hard limit but a guideline. The Victron MPPT Calculator allows 30% overpanelling as an option. The guideline for 30% overpanelling is based on the next size controller being more expensive and would be underused if matched to a larger panel array. If the next size MPPT is the same price then it makes sense to buy the larger MPPT.
I can not answer your other questions.
The 150 model allows an open-circuit voltage (Uoc) of 150 V, with a maximum charging current of 35 A.
If you might want to add three more modules in parallel at some point, I’d choose the 50 A controller.