Temperature and solar panels
Weather effects the performance of solar panels. Our solar panels have a standard temperature rating of 25 degrees Celsius, which is 77 degrees Fahrenheit. This means that for every degree over 77 the solar panels will reduce in voltage. And for every degree under 77 the solar panels will increase in voltage. The Titan solar charge controllers are rated for 35-145 Volts DC. This means they need at least 35 volts to start charging and will be damaged beyond 145 volts. If you live in a colder climate, you’ll want to know the maximum volts you can put into the Titan solar charge controllers without the temperature raising the volts beyond 145.
The information you’ll need in order to calculate your maximum voltage is as follows:
STC Temperature (Found on the panel label, ours is rated at 25 degrees C)
Record Low Temp (The lowest temperature recorded for your area)
Temperature Coefficient % (Usually between 0.3% and 0.5% our solar panels are highly efficient, rated at 0.29% if you are not using our solar panels and do not know the temperature coefficient % of your panels assume an average of 0.4%)
Voltage Open Circuit (Found on the panel label. Our 100W Flexible, 200W Rigid, and 200W Briefcase panels all have a slightly different VoC)
The formula for calculating is as follows:
(STC Temp – Low Temp) x Temperature Coefficient % x VOC + VOC = VMax
For this is example we will assume you have our Titan 1000W Rigid Kit which comes with 5 200W Rigid panels rated at 23.4 VoC. When wired according to our 1000W Rigid Kit wiring diagram, the total VoC would be 117. For this is example lets assume the lowest recorded temperature for your area is -10 degrees Fahrenheit which is -23 degrees Celsius (the calculation must be in Celsius) if we plug in these numbers to our formula it looks like this: (25 – -23) x 0.0029 X 117 + 117 = 133.28. According to this formula and with the example information, you would be safe to have an open circuit voltage of 117 going into the Titan solar charge controller year round, since the lowest recorded temperature does not increase the voltage above 145.