The charge controller, or regulator, has three primary functions. First, it provides a central point for connecting the load, the module and the battery. Secondly, it manages the system so that the harvested electricity is effectively used, and so that components (especially batteries and lights) are protected from damage due to overcharge, deep discharge and changing voltage levels. Thirdly, it allows the end-user to monitor the system and locate potential system problems.
When buying a regulator, always check its rating and which features it has. Always read and keep the user manual. Some controllers only have overcharge protection - which will not be of much service to systems that are constantly putting their batteries through deep discharge. Make sure you understand each of your controller’s features and, if you are the installer, how to install it.
Ballast inverter: a device which converts low voltage direct current to the type of high voltage ac current required by fluorescent lamps
Charge controller: a device which protects the battery, load and array from voltage fluctuations, alerts the users to system problems and performs other management functions
Charge regulator: see charge controller.
Converter: An electronic device for DC power that steps up voltage and steps down current proportionally (or vice-versa). Electrical analogy applied to AC: See transformer.
Mechanical analogy: gears or belt drive.
Inverter: An electronic device that converts low voltage DC to high voltage AC power. In solar-electric systems, an inverter may take the 12, 24, or 48 volts DC and convert it to 115 or 230 volts AC, conventional household power.
PV Array-Direct: The use of electric power directly from a photovoltaic array, without storage batteries to store or stabilize it. Most solar water pumps work this way, utilizing a tank to store water.
PV Lighting System: a system that includes at leat a PV module, a battery, an inverter and a light. Can include a large number of lights, preferably high efficiency fluourescent, LED, halogen lamps.