JoeSixPack said:
That's a bit confusing, because it's my understanding that a storage battery
does a fine job of leveling off the peaks and troughs in any circuit
connected to it.
The danger here is just too much bad advice. Now from your post:
"None of those concerns are mine for this application. My intention is
to supplement the charging of the photovoltaics when they can't keep up."
You can do this. You will need a regulator to control the charge.
You have three choices:
1) The reg built into the alt. Only if you are desperate.
2) A purpose built reg. Better control, better charging.
3) The reg you have between your ears. Works well, runs on full logic
but requires you to stay awake.
I believe you said 4 225Ah batteries. If that is in fact 500Ah all up (4
T105s series/parallel) then a 30 amp alt will be fine, 60A would be
pushing the friendship a bit. C10 would be 50A. But you want to bring
your batteries up faster than ten hours.This means you need a charging
regime to suit your needs.
My charger:
5hp motor, 35A Bosch alt(external reg type, reg not used) Rheostat for
field control. This is the famous 150A rated ceramic Rheostat scrounged
from a spot welder.
Take the state of charge in your batteries. Yes it is important that you
not let them remain at a low state of charge for long periods, on the
other hand they do not need to reach 100% charge every single day
either. I will run the little generator to charge my batteries if they
drop to 12 Volts (but like the fine print says ”Conditions Apply”)
Condition: Batteries read 12 volts at four o’clock in the afternoon
Condition: I know the sun won’t be out tomorrow.
Condition: I need to use the computer for several hours that night.
(This condition has been negated due to better computer.)
Condition: There will be three hours of Red Dwarf on TV that night.
It takes at least two of these conditions to warrant the running of the
generator. It may be that your "required" conditions will be different.
And when it comes to charging the batteries I am not trying to bring
them up to 100%. I am doing what I call ”Maintenance Charging” which is
to say that I only require that they be in the top twenty per cent of
their capacity. The sun usually does the rest.
When required I run the gen for less three hours. This is for a battery
set of 840Ah. During winter this may be as much as 3 hours a week or as
little as 1-2 hours/month.
Will this harm your batteries, only if you're stupid and don't pay
attention to what you are doing.
Oh, I also run a logger on my system so I know what is going on, at all
times.
George