Solar Voltaic Charge Controllers
Solar voltaic panel output should never be directly connected to a battery as the unregulated current from the solar panels will damage the batteries. The primary function of a Solar Charge controller is to fully and properly charge a battery bank without permitting reverse current flow to the solar voltaic panels at night.
Primary of types charge controller:
On/Off type Solar Charge Controller
Pulse Width Modulation (PWM) Solar Charge Controller
Maximum Power Point Tracking (MPPT)
Sizing the Solar Charge Controller
Most Solar Charge Controllers are rated by the amount of array amperage (current) and voltage they can handle. Amperage ratings run from 1 amp to 60 amps, voltages from 6 to 60 volts. Cold weather, reflection and edge-of-cloud light refraction can increase PV panel output. The charge controller should be sized to handle 25% more current than the panels are rated for. Most people add solar panels as they go along , size the charge controller to handle your needs into the future.