The Power Advantage 302 and Power Advantage 304 step-down battery chargers decrease incoming solar-generated voltage to optimize charging currents for battery banks. The chargers deliver up to 25% more dc power to the solar electrical system’s batteries from photovoltaic panels. By increasing the current to the batteries, the system maximizes usable power from solar panels to increase overall solar energy system efficiency and lower the cost of ownership. The chargers employ a proprietary Power Advantage II technology that is said to deliver more power than other photovoltaic chargers. The charger finds the maximum power point of the solar panels and constantly readjusts for changes in sunlight, temperature, and battery voltage. The systems easily retrofit into buildings with existing charge controlling systems. Both models have LCDs that show real-time system status such as state-of-charge. The LCDs also let users adjust set points such as charging voltage. The software runs on any PC with Windows 95/98 and a serial port. The 304 data can be downloaded via modem to spreadsheet programs for monitoring and historical analysis. The 302 does not offer data logging outputs.