Morningstar Controllers

The main function of a controller or regulator is to fully charge a battery without permitting overcharge or reverse current flow at night. If a solar array is connected to lead-acid batteries with no overcharge protection, battery life will be compromised. Simple controllers contain a relay that opens the charging circuit, terminating the charge at a pre-set high voltage and, once a pre-set low voltage is reached, closes the circuit again, allowing charging to continue. More sophisticated controllers utilize pulse-width modulation (PWM) or maximum power-point tracking (MPPT) to assure the battery is being fully charged in the most efficient manner.