A Maximum Power Point regulator can provide a good alternative for boats with limited space for additional solar panels.

If someone walked up to you at a boat show and offered to sell you a black box that would increase the output of your solar panels by 30 percent you might still be laughing—but we’re talking about an MPPT (Maximum Power Point Tracking) solar panel charge regulator, and it’s real.

A charge regulator really has only two functions on a solar panel: to block a small reverse current flow back into the panels at night and to regulate the voltage to prevent overcharging. Before MPPT came around, existing types of regulators—even sophisticated pulse width modulation (PWM) regulators—failed to address a problem unique to charging batteries with solar panels. Solar panel…