Solar charge controller selection help needed
I am looking to put in a solar system that will produce about 30 amps per day. I choose a semi-flexible 135 watt panel made by Sunpower which meets my capacity needs. My only problem is choosing t...
Forum Discussion
I run two 12V panels in series for a 12V bank. The Vmp of a panel is 18.3V. I measure 36V+ at the controller terminals. I believe my wire size should be calculated using 36V. I am using the existing 25rt feet of 12Ga wiring.
I'll guess the Vmp of the subject 24V nominal panel at 33V as that is common. In series we should expect 66V at the controller. Let's say the conversion loss down to 12V is 3% at 33V and 6% at 66V. Now when we figure the total of wiring and controller losses, we do worse at 66V for the same size wiring.
I did ask for those specs.
HTH;
John
I'll guess the Vmp of the subject 24V nominal panel at 33V as that is common. In series we should expect 66V at the controller. Let's say the conversion loss down to 12V is 3% at 33V and 6% at 66V. Now when we figure the total of wiring and controller losses, we do worse at 66V for the same size wiring.
I did ask for those specs.
HTH;
John
