The wording on their specs is odd to me; it reads like a hard limit on the watts. It’s not.could potentially see 999 watts. I wonder if Epever overlooked that
The hard limit is volts. You need to respect that religiously.
Overpaneling- despite the odd english in their specs- is fine. Over voltage is not.
If you are wired series to use high volts and maintain panel amps, the epever will provide output up to the amp rating if 40 or 60 at the set volts.
So it is conceivable you may charge at 100% of 40A but actually have unusable watts. (this doesn’t bother me; the goal is to have enough electricity and give yourself max battery life)
the lower voltage goal u mentioned weather related?
The sun affect on panels after cold temps was interesting. Doesnt apply to me
As the temperature goes down, the panels’ output voltage goes up. There are formulas and constants for this, but essentially (unless the 20% puts you close to or at the SCCs max volts) you are ‘generally’ safe if sum of VOC produced is 80% or less of charge controller max volts the factory smoke won’t be released. The temperature is important- not the weather.
So temperature does effect you.
Then there’s the battery type: as 32*F is approached, lifepo can be damaged by a high charge rate; below 32? Charging needs to shut down.
Lead Acid batteries can be charged well below freezing, albeit technically the rate shouldn’t be extremely high. Can’t recall the preferred c-rate. For small wattage systems this is sortof taken care of by the limited panel watts, but even 600W systems may actually need more attention to assuring distilled water is added as needed to keep the electrolyte over the plates.
So the temperature does effect you.