We tested the two wires that were capped by our cab battery.
They are live and might wired for a positive cable disconnect switch (though everything I have read says it is better to put the disconnect switch on the negative terminal).
Trying to trace them just gives me a nice warning tingle - like a good 9v battery on your tongue (the way 9vs were tested for charge when I was a kid).
I can’t do it visually so I was doing it by feel. We would have to take the battery out to double check but I bet there is a diode or breaker or something behind that battery I am touching that had the a wire from the positive side of the cab battery.
We planned to put a battery disconnect switch for our coach batteries. We like the idea of it being inside the coach - on the wall just inside the door where the generator switch and battery monitor is now, but there are advantages to having it in the battery compartment (mucking with batteries and it is right there).
I don’t like there idea of the on the terminal battery switches - they seem a little flimsy to me (I haven’t seen on in person. Just pictures & descriptions).
BEP seems to make some nice ones -
Battery Switches | bep (http://www.bepmarine.com/en/products/battery%20management/battery%20switches)
Jane
Our LD has a marine battery switch.
It allows connecting the starting and coach batteries together or shutting the coach battery off.
BLUE SEA SYSTEMS Heavy-Duty Series Battery Switches | West Marine (https://www.westmarine.com/buy/blue-sea-systems--heavy-duty-series-battery-switches--P009_272_004_506?recordNum=1)
In case the starting battery dies, the engine can be started with the coach battery.
Old battery and tray removed | New battery switch with jumpe… | Flickr (https://www.flickr.com/photos/lwade/1415588249/in/album-72157602104740457)
The switch is rated at 500-amp, more than adequate for starting the engine.
The primary wiring, between the batteries and the battery switch, are wired with 2-gauge welding cable.
Battery tray- new | Flickr (https://www.flickr.com/photos/lwade/sets/72157602104740457/)
Have you included surge protection and voltage protection in your plans?
You can use a surge and voltage protected ATS or an inline surge protector, wired between the transfer switch and the power center..
Automatic Surge Protected Transfer Switch (https://www.progressivedyn.com/rv/automatic-transfer-switches/pd52dcs-pd52s-240-vac-50-amp-automatic-surge-protected-transfer-switch-the-silent-ats/)
Progressive Industries, Inc. | Rv Surge Protection (http://www.progressiveindustries.net/ems-hw30c)
https://www.amazon.com/Progressive-Industries-EMSHW30C-Surge-Protector/dp/B0050EGS5W?SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-d-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B0050EGS5W
Larry