Maine & Stu
Thank you both.
Yes I am not concerned abut the 4mA of parasitic drain 24/7 of the Blue Seas ACR because I also have a Link 1000 - standing current 41 mA, an advanced Adverc Alternator controller - 5mA, a Navtex engine for laptop - standing current 45 mA, a burglar alarm - 2 mA, a Solar Controller - 22 mA and a bilge pump 5 A but only when running - all on my 'Always On' circuit.
And, of course, a solar panel to keep up with all this.
My conventional (OEM supplied) simple relay combiner became intermittent at about the time Blue Seas emerged as a supplier of marine electrical goods so I purchased the Blue Seas ACR (single input model).
I measured the ACR 'ON' current, also with Fluke DVM, at 200 mA and saw little future in guaranteeing I ran the batts down to 13.8v having just taken the trouble to fully charge them.
Then again, I charge my engine start battery as a priority so the ACR went into the dreaded slow chatter with 360 Ah across 85 Ah. It has circuitry that prevents it fast chattering.
Anyway I chucked up my combiner and turned the rim off, cleaned and reset its contacts, sealed it up with epoxy so it is now properly sealed and I put it back on board.
All nearly a decade ago.
No problems since.
Stu - I guess I am no different than anybody else in that I forget to turn things off. Easy to discover one needs to turn them ON but OFF - I can't be trusted. So yet another switch would be anathema.
The responsibility of owning a modern boat is onerous. I already have one that could only be sold to another electrical/electronics engineer as anyone with less skills would soon get into a pickle.