I cannot see your point Chris, of course the cable capacity would be in excess of the alternator capacity. If you fit a 600 amp alternator then the cable would represent that and more.
Correct the load is applied to both sources at the same time, which is not per your post earlier which I was contesting.
With the conversation moving to other batteries ect is just muddying the waters, so to keep it clear they can be put aside.
At the end of the day I was addressing your statement "I'm not the best person to advise on all of this Stu. But really when winching, you aren't pulling from your
alternator are you. Draw can be up in the region of 500 - 600 amps so you're pulling from the battery" Chris that is not correct.
So to be clear, if when you flash your headlights the engine note changes, it is because the alternator responds to the load.
If you apply a winch load then again the alternator responds, it will simply put out it's maximum capability at whatever revolutions it is being driven at.
So now change the alternator to the theoretical 600 amp unit and of course the cable. Now when you flash your headlights the alternator responds in the same way, now apply winch load, again the alternator does exactly the same, but this time nothing needs to be drawn from the battery.
Another example would be a winch load of 600 amps, but now the alternator is a 500 amp unit in this case the alternator would max out again assuming sufficient revolutions, but now the battery would supplement the alternator.
Apologies for the 'load on belt' analogy, I was not trying to be clever, just not very good at getting my point over, and given my experience I can get a little frustrated when trying to explain something that I have been working with for over 40 years.
To the DC 2 DC charger, if you have a specific need to have one then that is great, I agree they have their place, but they are not for me.
As an aside, I fitted a Blue sea VSR and a separate NL monitor around 6 - 7 years back and no issues.
I am not a lover of the 'all in one" units, they can disguise faults, only found out by chance, or worse when you really need their performance.
Regards
Dave