Dual battery set up advice

Good point there re circuit breakers.
Never had them trip but I have a in line battery monitor so can see straight away the voltage going to & from the batteries.
Forgot to mention that additional monitor & mate has one that goes thru bluetooth to the phone.
Cheers
Stu

One more thing. The circuit breakers I used were around 50 or 60 amp to deal with a dead short in main wiring.
All other circuits are individually fused with the automotive 10 & 15 amp fuses as required.
Cheers
Stu

Bushranger, you mean the monitor is reading the amps , I think. The voltage simply takes care of itself.

Can read volts & amps.
The volts give me an idea of the state of discharge when stationary for a while.
Also lets me know at what point to setup the solar panel & watch voltage rise confirming solar or charging circuit is functioning correctly.
Cheers
Stu

Thats why I miss the fuseable link wire yazaki used to make. I blame internet forums for its demise.

QLD
You can reset a breaker or replace a fuse as needed, but no one carries or easily obtains a specific FUSIBLE link and so the vehicle or system is rendered inoperative. They were a really stupid idea and when they fractured on early Toyota’ they left the alt charging the system but not attached to the battery, so devices got a nice surge of 80 v or so and subsequent current forced through them to destroy them. What a nice thing to happen. I have had experience with fusible links causing the above.

Yep when used in applications that they were not suited for they would fail as would anything else. They were used as a main fuse built in to the harness of Holdens from 1964 till the VB commodore and had so little trouble very few people even realised they were there.
The alternator on these vehicles were not running through it, in fact they were not fuse protected at all.

Agree withqldcamper, fusible links for under bonnet, the wire type, they have been used for a long time in cars and cause few issues. The new plastic plug in types not so good. If you have made up fusible links for your project then spares aren't an issue as you would make your own spares.

I would recommended either fusible links (wire type) or bolt down fuse fuses simialr to the below, never had any issues with them:

bolt down fuse


Terminal fuse

Another little advantage I use a lot is the fact that fuseable link wire runs warm to hot by nature ( and yes I understand that means voltage drop but it is neglagable ) so by a touch you can get a feel for how hard the system is working without the need for any instruments.
I run a manual reset cct bkr at the crank battery end and the output from the BCDC and a 4 inch black fuseable link at the ACC battery.

Yea fuses or breakers work if you spec them right.
Think I like being a bit more scientific than how warm the fuse is running to judge the system performance.
Volts & Amps meter hard wired in tell you at a glance what is happening. If your really up with technology then as I said earlier you can read via bluetooth to your smartphone.
Cheers
Stu

Yes,

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That should be a conditional "yes".

If your isolator is a solenoid of the voltage-sensing type (as distinct from ignition-controlled) then there may be a problem with locating it remote from the alternator. Typically, the voltage-sensing isolator will energise at 13.2v and de-energise at 12.7v. When the isolator senses 13.2v coming from the alternator and connects the aux battery, current begins to flow and a voltage-drop will occur in the cabling from the alternator. If this voltage-drop is sufficient to reduce the voltage applied to the isolator below 12.7 volts then the isolator will drop out and the process will be repeated ad infinitum and the aux battery will not be charged. It all depends on the state of the aux battery and the capacity of the cabling.

It is better therefore, that the isolator is positioned close to the alternator in order to sense the applied voltage.

What Allan said, with one possible exception. IF the sensing terminal of a VSR is (or can be) separated from the "power in" terminal AND a separate line run to it from the cranking battery, then you would be able to locate it near the auxiliary battery.

Whether running that extra cable is something you WANT TO do is up to you.

Another option for a smart isolator remote from the crank battery is to use a dumb solenoid and then a small, adjustable VSR such as this one to control it. You can then tailor the cut-in voltage to suit your setup which might be affected by a so-called "smart" charging system and/or voltage drop in the cabling.

May as well just buy a smart programable VSR.

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Considering the hassles of the options above, I would ask why on earth one would consider placing the isolator anywhere but near the alternator?