Why does generator power work so much differently than solar?

Freewilley

This has been bothering me for a while.
When I have no solar, I turn on the generator for 2 hours or so in the morning.
It charges at 900watts.
As it runs, the voltage increases and charging eventually decreases. Lets say it reaches my max at 14.8, the generator charging has dropped to 100watts and of course it takes care of power demand from the house.
That 100 watts and voltage of 14.8 stay static as long as the generator runs, even with no solar of consequence.

I turn off the generator and voltage immediately drops off. Right now as the day moves on,  I am pulling 320 watts of solar and the voltage reads 13.2, with very little power being consumed.
So the generator seems to maintain the voltage very differently than the amount of charging going on.

To back this up, I know that when I have had a good solar day and have been at 14.8 for hours, when the sun starts to recede that voltage drops quickly. Even 600watts of solar, and probably more, are not enough to maintain that high voltage ....that the generator seems to be able to maintain with only 100 watts with ease.

What is the explanation for that?

jonr

Sounds like that charging algorithms are different when running from the different sources.

Freewilley

I was going to delete this thread as I feel like a knucklehead....as the day goes on, I see that the system is only drawing 320 watts from the solar alone and is maintaining 15.0 voltage. Given that I am using a little power in the house, this is not the concern I thought it was....the difference is much smaller....

my bad.

westbranch

BUT you should still have a look at the algorithm of/ for your AC charger....  it may be close but not exactly the same and for different battery brands this can be an important thing to know... especially when you have AGMs or ? batteries...  not a bad question, us older forum haunters (may) know about the differences but new folks may not... they might  just assume a charger is a charger, all the same...

mike95490

My generator and charger can only get 64VDC, my solar controller can do 68VDC  Is that the question?
or is it
The solar cant run the same loads as the generator can ?   Surge limits and Power Factor are the culprit.