Portable panels wire size

Almot wrote:

AStinker- wrote:
But isn't the input voltage still important somehow? If not why are we worried about voltage drop from the panels to the controller?

With MPPT the drop is important because this converts into lost amps and amp-hours.

With PWM - people more familiar with these low-tech devices ;) will correct me if I'm wrong - the voltage drop is not important as long as it is not lower than the highest Absorption voltage that you might need, i.e. Absorption on a cold day. As noted, and I agree, that it should also not be higher than 15V on a cold day.

So 15V is your lower limit of input after voltage drop at 77F. If it's lower, the controller with temp-comp won't be able to raise it as needed on a cold day. Controller with temp-comp will be able to lower it down from 15 on a hot day.

OTH, your controller should have means to limit maximum output to 15V - maybe it already has it as factory-preset. My controller has adjustable upper voltage.

Are all you PWM guys going to let him get away with that?? :E

Yes sir, it will have to have a means to limit maximum output to 14.8 or 15V because over 15 volts will shut the Inverter down. And because I'm going to be a power hog with the freezer it appears to me I will want the absorption voltage as close to 15 volts as possible also. Right?? So is 15 volts the the magic number?? The controller has to limit output to 15 volts or slightly less therefore the "voltage at the end" of the cable from the solar panels into the controller need to be or "should be" 15 volts or above?? Yes?? No?? I'm going to sleep on it now and wait for all you guys to make my day or burst mt bubble. :B Why do I feel like I'm missing something??