I wouldn't say you are a broken record, but you may be going around in circles. I want to straighten you out (even though I get along better with bent people!).
If your "stator" isn't an alternator, what is it - a generator, or a motor?
If your "stator" is "constant current", does it keep increasing the voltage until the load accepts the the current?
I think you will find your charging system is an alternator. (Alternators have a stator and a rotor as do generators and motors).
Not that (I think) it makes any major difference - it outputs whatever power at whatever RPM.
I also think you will find it is NOT a constant current system, but capable of a certain (max) current at a certain speed/RPM.
We could do the complex theory - like a X,000W RMS amp at 1/2 volume hence 1/4 power hence (X,000/4)W RMS hence (X/4 x 1000W/12V) Amps required and will the "stator" keep the battery charged if an average of Y RPM?
What about the "frack that crap" approach?
Instead, take your pick - is my system up to it, or is my system STILL up to it?
(IE - it was big enough, but are my alternator brushes deteriorating; is that new amp to big' etc?)
The solution - a voltmeter.
A voltmeter (at the battery!) tells you everything.
EG - above ~13.6V - we are charging.
- above ~14.4 we are overcharging.
- 12.7-13.6V - we are charging, but not at full voltage. (Ok, so our load is bogging down the alternator, or the alternator isn't big enough, but...)
~12.6-12.8V - battery is fully charged.
~11.6-11.8V with no load - we have a FLATTERY (Flat Battery - a term AFAIK coined by a Darwinian (in Aus) known as "Paddles")
10.6V - the general "worst case" voltage for a battery assuming a load.
I am now talking the bottom line.
It doesn't matter what know-it-all R-Soles like OldFart think your system can do (based on your supplied average RPM with average Watts-volume output etc).....
So your 1,000W rated alternator happens to put out 10,000W at 3RPM, or your 250A alternator only puts out 50A at 2,000 RPM.
Is it enough?
Voltmeter.
The ultimate confirmation.
Does that make sense?
Do you require further clarification?
Mind you, IMO, I love redundancy - and that's for cars etc.
In a boat, I would DEFINITELY want a second battery. (Unless you have a back-up rope-pull, or good enough fins/flippers to push start?)
BTW - here in Aus being "down under", we merely pull out our sea-anchor. We then start falling down hill and eventually gain enough speed to start our outboard/inboard engine. It's equivalent to push starting a car (downhill).
I've been told that you can't do that in the northern hemisphere. Apparently water there is "flat". Is that really true - or just more "I read it on the internet" bullsh?
But back to serious doodiee...
I just purchased a pre-loved 12V refrigerator that I am currently (no pun) testing. I'm running it off a 12V battery with no charger. So why is its voltage higher now than when I started? Is my DVM (meter) battery flat, my DVM stuffed, or is it AC being "reflected" by the fridge's inverter? (Damn - I should have bought that Tue-RMS multimeter!)
Alas, a few of the complexities of electricity for us peasants with inadequate primitive tools.
But we make do. Do you have a multimeter? Or a voltmeter that you can connect across the batteries?
If so, you should be able to get a feel for what RPM for what "volume" output (with/without lights etc).
40-45A means about 500-650W max output.
The capacitor has negligible effect on reserve time.
I connect my 2nd battery directly to the alternator (across the 1st battery) ONLY whist the alternator is charging.
The batteries are otherwise isolated.
Hence I have my untouched 1st battery for engine cranking etc irrespective of whatever the load (fridge, amplifier) does to my 2nd battery. That relates to my "redundancy" desire mentioned above.
And I hear the birds chirping. I think it's time for bed!
Thanks too for you compliment!
ZZZzz...
Peter.