In stand-alone photovoltaic (PV) systems, charge controllers regulate the current from the PV array in order to protect the battery from being overcharged. In addition controllers regulate the current to the load, thereby protecting the battery from deep discharges. The charge controller is therefore the energy manager in a stand-alone PV system, ensuring that the battery is cycled under conditions which do not reduce its ability to deliver its rated capacity over its expected lifetime.

OSS procures charge controllers from world class manufacturers like Digital Solar Technologies (DST) USA, Morningstar Corporation USA, Steca Germany etc. Each of the Controllers address the needs of very specific requirements.

Digital Solar Technologies (DST) specialize in microprocessor based power system controllers and supply innovative control solutions for PV/hybrid and grid tied power systems. DST controllers range from stand alone PV applications needing advanced controls, to multiple power source systems requiring varied I/O monitoring and control needs including data logging with remote monitoring.

Morningstar Corporation is a world-leading supplier of photovoltaic (PV) controllers using advanced technology. Morningstar's TriStar, ProStar, SunSaver, SunKeeper, SunLight, SunGuard etc. brands of controllers have been recognized in the international PV markets as the most advanced and of highest-quality controllers.

These controllers have the following characterisitcs as noted below:

• Reliability: Exceeds all other PV controllers for protection against lightning surges and the harsh operating temperatures common to remote PV systems.
• Battery Charging: Advanced PWM, constant voltage, pulsing charge algorithm results in an increase in battery capacity and operating life.
• Value: Competitive in price with lowest cost controllers in the industry. The low cost structure, coupled with advanced features and performance, make Morningstar's controllers the highest value products in the industry.
  

The Steca range of charge controllers are ideal for small and medium solar PV applications.