Solar Charge Controller / MPPT Calculator ⚙️

How to Use the Solar Charge Controller / MPPT Calculator

Enter panel wattage, open circuit voltage (Voc), number of panels, and battery voltage. Formula: MPPT output current (A) = (panel watts × panels × 0.97) / battery voltage. Required rating = output current × 1.25 (NEC safety factor).

MPPT controllers are recommended when panel Voc exceeds 1.5× the battery voltage. MPPT converts excess voltage to current, recovering 15–30% more energy than PWM at the same array size.

Standard controller sizes are 10, 20, 30, 40, 60, and 80A. Always size up to the next standard size above your calculated requirement. For parallel-wired panels, array Voc equals single-panel Voc.