Victron solar sizing tool
Which Victron MPPT do I need?
Enter the numbers from your solar-panel label. We check cold-weather voltage, current, and charging capacity against Victron’s published limits, then match you to a controller we stock.
Tell us about your system
Use the electrical specifications printed on the back of one panel. All panels should be the same model.
Array layout
From the panel label
Where the boat goes
Where do I find Voc, Vmp, and Isc?
They are on the specification label on the back of the panel, usually listed at STC (standard test conditions). Pmax is the wattage. If the label is worn or missing, take a clear photo of it and call Anthony before buying.
Your preliminary match
Conservative sizing with 10% voltage headroom below Victron’s limit.
Cold-weather Voc
Panels make more voltage in the cold. We correct Voc for your coldest temperature and stay 10% below the controller’s hard limit.
Short-circuit current
Parallel strings add current. Total array Isc must stay within the controller’s published PV input limit.
Charging capacity
Victron recommends up to 130% PV oversizing. The controller trims the rare peaks, and annual harvest loss is usually under 1%.