My Vantage Pro 2 Plus (6163) has been in service for about five years. I replaced the fan and batteries two years ago. I was doing spring maintenance last week and noticed that during the day, the fan was not running. I have ordered the combo fan/battery replacement kit (7758B) and plan to to the repairs this weekend. It occurred to me that perhaps the solar panel powering the FARS may have also gone south.
Does anyone know what the nominal output voltage of the FARS solar panel is?
While I might have a lot to learn in the area of meteorology, I do have a vast amount of knowledge & experience in the area of solar power and batteries.
The Davis Photovoltaic (PV) modules are made of monocrystalline silicon wafers encapsulated with an acrylic resin. The life of mono silicon PV modules is about 50+ years. Though the industry standard for output above 80% is 20-25 years. There are no moving parts to wear out. The tiny foil buss lines can sometimes crack or split but this would take a lot of flexing and you would only lose a percentage of power. You can get 'snail trails' which are areas between buss lines that short and leave crooked, blurry brown lines. But again, only a small amount of loss. So unless there is a clear break in the conductors connected from the + & - terminals to your equipment, (in which case you could repair or replace the wire), corroded contacts or the loss of transparency in the resin, I'd rule out an issue with the panels 'Going Bad'.
In the Davis 24hr FARS system, as with most solar / battery storage systems, the weakest link is the batteries. Especially in a daily charge/discharge cycle.
Rechargeable batteries have a finite number of charge cycles. some as low as 300 to as high as 1000. Once this number is reached, the batteries are no more good.
Next wound be the fan motor, then the conductors and connections in between, and last, the PV panel.