P v voltage

[btemplet]

I need help. I have 40 volt coming from my solar panels all the way to my charge controller when I connect it to my solar controller the volts dropped to 20 V. Is that normal?

 

[ricardocello]

Yes, if the solar controller is an MPPT, it adjusts the voltage and current to maximize available power from the panel.

If the solar controller is a PWM, the load applied will bring the voltage down.

 

[SplitUniverse]

What you measure with no load is Voc, what you measure once the MPPT is connected should be Vmp or close to it.
Grab the panel specs and see if you are close to that (there's a temp compensation calculation as well so you will not be spot on).

 

[btemplet]

Thanks

 

[btemplet]

Thanks

 

[btemplet]

Thanks you