Calculating panel load for pwm controller

[Bluedog225]

Would I be pushing my luck to have four (4x) 100 watt panels in parallel on a the Victron BlueSolar PWM Pro Charge Controller 12/24V-30A.

This calculates out to 33.3 amps.

But I’m under the impression that the voltage both open circuit and under load is higher than 12. And that the panels rarely product 100 watts each.

If I adjust the collective panel output to 90% I get 360 watts. And if I adjust the voltage to 13 volts, the calculation changes to 27.7 amps.

I don’t know how to adjust for a cold day. We can get down to 10-20 F occassionally.

I’d rather not smoke the little controller and can be quite happy with the three 100w panels I have but wouldn’t mind getting the most out of it.

Thanks

 

[FilterGuy]

I don’t know how to adjust for a cold day. We can get down to 10-20 F occassionally.

Adjusting Solar Panel Voc for temperature

When designing you solar panel system, it is important to adjust you solar panel Voc for temperature in order to ensure you do not over-voltage the PV inputs of your solar charge controller. This paper shows how to calculate the Temperature...

diysolarforum.com

 

[Texas-Mark]

Would I be pushing my luck to have four (4x) 100 watt panels in parallel on a the Victron BlueSolar PWM Pro Charge Controller 12/24V-30A.

I’d rather not smoke the little controller and can be quite happy with the three 100w panels I have but wouldn’t mind getting the most out of it.

IMO, if your PWM controller can't handle available panel power, you need a better controller. I have a Xantrex C60 that I frequently run 80 amps through with no issues. Note; I do have cooling fans on it to keep it from throttling down due to heat. It's rated to not shut down until 85 amps (it assumes a short).

BTW, the controller is not going to put out more than you are demanding from it, no matter how many panels you have.

 

[Bluedog225]

Thanks. I accidentally double posted this thread.