Summer 2009 (June 1 - Oct 24, 2009) Note that 12 rooftop panels feed directly into the batteries via the Outback MX-60 charge controller and are not accounted for by the Sunny Boy system. Thus the "true" solar PV input is about 31% higher than that shown on the Sunny Boy web site.
Winter 2009-10 (Oct 24, 2009 to June 1, 2010). The "Flexnet DC" battery monitor is programmed to turn off its auxiliary switch once the batteries reach 100% capacity, and to turn on the switch when the capacity drops to 90%. This switch is wired to a relay that connects/disconnects the sunny boy "B" inverter, which has 30 solar panels connected. Sunny boy "A" is connected to only 9 panels, and remains unswitched. Its operation reflects the ambient solar conditions outside. During a typical sunny day, this results in a large power drop during the day caused by switching off sunny boy "B". The Outback inverters are also programmed to switch on a 900 watt heater when the battery voltage exceeds 60 VDC. The heater load does not appear on the main power meter. Note: 12 panels are connected to the batteries via the MX-60 charge controller, as described above.
|Solar panel allocation - winter 2009|
|# rooftop panels||inverter/charger||notes|
|12||MX-60 charge controller||modulated to keep battery charged but not overcharged|
|9||Sunny Boy "A"||always on, unmodulated|
|30||Sunny Boy "B"||switched, unmodulated|
|18||removed June 2009||will remount 2010 to MX-60|