Fire, Wind & Rain Technologies (Flagstaff, AZ) is offering the new Power Advantage 302 and Power Advantage 304 battery chargers. The new systems are "step-down" chargers designed to decrease incoming solar-generated voltage to optimize charging currents for battery banks.The 30A chargers are claimed to deliver up to 25 percent more dc power to the solar electrical system's batteries from photovoltaic panels. By increasing current to the batteries, the system maximizes usable power from solar panels to increase overall solar energy system efficiency and lower the total cost of ownership, according to the company.Both models incorporate Fire, Wind & Rain's patent-pending Power Advantage II technology, which is claimed to make the Power Advantage 302 and 304 able to deliver more power from PV panels than any other battery chargers. The charger is designed to find the maximum power point of the solar panels and constantly re-adjust for changes in sunlight, temperature and battery voltage. The chargers offer an LCD that provides real-time system status such as state-of-charge and time left on battery based on current usage. The LCD also enables the user to adjust set points such as charging voltage with digital precision. The Power Advantage 304 allows collected data to be downloaded via modem to a spreadsheet program for monitoring and historical analysis. Virtual control panel software, which runs on any PC with Windows 95/98 and a serial port, monitors the system to show historical and real time system data regarding voltage, current, power of PV panels, status of the charger, battery voltage, available battery capacity and battery temperature. The Power Advantage 302 does not offer the same data logging capabilities, but can be upgraded in the field to offer the same capabilities as the Power Advantage 304.The Power Advantage 302 is priced at $449, and the Power Advantage 304 is priced at $549.