Solar Charge Controller Calculator

Infinite Power Supply Resource Tool

Solar Charge Controller Calculator

Size an MPPT solar charge controller for RV, marine, van, cabin, and off-grid battery systems. Enter your panel specs, battery voltage, and solar array layout to estimate controller voltage and amperage requirements.

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Built for real off-grid layouts

Checks array watts, cold-weather voltage, controller output amperage, PV short-circuit current, and fuse guidance in one easy tool.

Solar Array Inputs

Tip: Voc, Isc, wattage, and temperature coefficient should come from the solar panel data label or manufacturer spec sheet.

Results

Total Solar Array—
Cold-Adjusted PV Voltage—
Required Output Current—
Array Short Circuit Current—

Recommended Controller

Enter your solar panel specs to calculate a recommendation.

Guidance only: Final equipment selection should account for the charge controller manual, wire length, conductor size, fuse/breaker ratings, installation environment, and applicable electrical code.

1. Match PV voltage

Your controller PV input voltage rating must be higher than the array’s cold-weather open-circuit voltage.

2. Match charge current

The controller output amperage should be sized for total solar watts divided by the battery bank voltage, with a practical margin.

3. Verify wiring protection

Parallel strings can increase current. Use properly rated PV wire, breakers, fuses, combiner hardware, and disconnects.

Need a complete RV or off-grid solar package?

Infinite Power Supply can help match panels, MPPTs, batteries, inverters, cabling, fusing, and install-ready accessories.

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Wire Sizing Chart

Fuse Sizing Chart