Checking solar output

[funflair]

Ok thanks for the info I have done as suggested above and covered the panels one at a time, with both of the 100w panels covered there is no drop in output, with both uncovered and covering the 175w panel there is no

I would put the 2x100watts into their own MPPT controller, that way if they are a different spec to the 175watts they won’t mess each other about.

 

[nickq]

The output from the controller at 13.5v will be 14.8 amps or 14.1 at 14.2amps..

Good point, I forgot it will output at the lower voltage. So with the 375w at 13.5v that would be 27amps if the controller allowed it. My controller outputs at 14.3v. 6 amps still doesn’t make sense though.

 

[Lenny HB]

Good point, I forgot it will output at the lower voltage. So with the 375w at 13.5v that would be 27amps if the controller allowed it. My controller outputs at 14.3v. 6 amps still doesn’t make sense though.

I know Victron MPPT controllers are OK with too much solar going in just outputs it's max.

In this case with the PWM controller if it gets too hot its output is cut to a few amps so with too much input this could be the problem. (That was my interpretation of the Victron info I just read).

 

[Raul]

Good point, I forgot it will output at the lower voltage. So with the 375w at 13.5v that would be 27amps if the controller allowed it. My controller outputs at 14.3v. 6 amps still doesn’t make sense though.

Forget ALL that, this is a pwm controller, which means, amps in from solar=amps out to the battery AT battery voltage. Forget the higher voltage, the pwm will just chop it and waste it. So add the solar amps AT battery voltage, that’s it.
With mppt it has a dc-dc converter, and will be power in=power out minus conversion losses. On this example it is not the case.