Morningstar Prostar 25A MPPT Solar Charge Controller...

High Reliability – conformally coated circuit board, corrosion resistant terminals, premium high-frequency CoilCraft inductors, over-spec’d components, transient surge suppression, and lowest published failure rate in the industry.
Maximizes Energy Harvest – using TrakStar MPPT Technology to determine and adjust to the true maximum power point as solar insolation changes throughout the day.
High Efficiency – at low, medium, and high output power levels to maximize energy harvest and minimize heat buildup inside the controller.
MODBUS Communications – Solar Industry Standard MODBUS communications protocol allows for easy programming, control, remote data access and charge synchronization.
Fanless design for long-term reliability–no moving parts to fail, no dirt and debris sucked into the controller, and no parasitic load to reduce efficiency.