Enter your panel specs and wiring to get the correct MPPT current rating, cold-weather Voc check, and recommended controllers \u2014 with ecosystem-aware suggestions.
System Settings
Panel Specifications
Watts
100W
Voc
22.5V
Vmp
18.9V
Isc
5.8A
1S \u00d7 2P = 2 panels
Buy a 25A MPPT
2\u00d7 100W panels \u2192 200W array at 12V
Array Watts
200W
Charge Current
16.2A
Min MPPT Size
21A
Buy This Size
25A
Array Voc (STC)
22.5V
Cold Voc (0°C)
24.2V
Array Vmp
18.9V
Min Vmp Needed
13.8V
Wiring: 1S \u00d7 2P \u00b7 25A MPPT at 12V
MPPT charge current: 16.2A × 1.25 safety = 20.2A minimum → buy a 25A controller.
Recommended Controllers
Victron SmartSolar 100/30
Most popular Victron MPPT for van builds
~$180–$220 AUD
30A \u00b7 100V max
Victron SmartSolar 100/50
High-output, Bluetooth, VE.Direct
~$280–$340 AUD
50A \u00b7 100V max
Victron SmartSolar 150/35
High Voc for series strings, Bluetooth
~$240–$290 AUD
35A \u00b7 150V max
Victron SmartSolar 150/70
Large arrays, high Voc, Bluetooth + VE.Direct
~$420–$500 AUD
70A \u00b7 150V max
MPPT sizing rules
MPPT current = (array watts × 0.97) ÷ system voltage × 1.25 safety factor. Always round up to the next standard size.
Voc rises in cold weather — about +0.3% per °C below 25°C. A panel rated 22.5V Voc at 25°C becomes ~24.5V at -10°C.
Series wiring raises voltage — allows thinner cable runs from panels to MPPT. Keep MPPT close to the battery, not the panels.
Never exceed the MPPT's max Voc — even briefly on a cold morning. This is the most common cause of MPPT failure.
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