Issue with SML III 5.5k during Fog Weather

[Raikoh]

Hello, my new system with 8 340w solar pannels in series connected to SML III has issue figuring the right voltage if there is very low light during fog and there is not a single direct sun light ray hitting the panels during the day.
My array is about 300+ volt but during fog the MMPT will stay around120volts making the total watts lower than it should be.
If i connect my generator on ac input for a few seconds, the mppt goes back to finding the "normal" voltage again and charging improve by about 2.5x

is this known issue on those kind of all in on charger? i found a work around but it's kinda bad that i have to start the gen for 2 secs to get my full charging capacity.

 

[Crowz]

My array doesn't make anything when its foggy so it seems what your seeing is normal to me.

As for it going back to doing a bit more than is normal for some controllers. Once they lock on a charging spot they don't recheck often enough to get out of the rut they are in. Some controllers are much more aggressive such as victrons.

 

[OzSolar]

(LOL.... @Crowz just beat me to this one! Some us are going back to unanswered threads trying to answer them)

I am not familiar with an SML III. I assume this a charge controller?

For what it's worth there's not much energy (watt hours) to collect in the low light conditions that you mentioned so as long as it runs fine in better conditions I wouldn't worry about it.

Wattage is far more important than voltage in this situation. Does the SML III have a wattage read out?