Blue Sea 7650 Dual Battery Install Question (2 Viewers)

[84 yota dude]

Calling all wiring professionals out there.

I am looking to install an aux. battery in my 1987 4Runner to power a fridge for an upcoming trip.

My question is does the Blue Sea 7650 need to be wired as displayed in the diagram in the instructions? The diagram makes sense, but the aux battery would always be connected to the main battery to charge when in the "ON" position. Would it be possible to wire it so the aux. battery is connected to the start battery to charge when in the "ON" position only? Idea is to not always have the aux battery charging. Maybe this defeats the purpose of the system but in my mind it seems like an easier install.

I was googling and found a thread on a boat form with a diagram showing what I am thinking (post#10). https://www.thehulltruth.com/marine-electronics-forum/421319-blue-sea-add-batter-7650-a.html

What do you guys think?

Blue Seas is not open on the weekends for support and I wanted to get ideas before calling them.

Also, found this helpful thread on here but it is wired as displayed in the Blue Sea instructions. Blue Sea Dual Battery Install - https://forum.ih8mud.com/threads/blue-sea-dual-battery-install.701384/

 

[84 yota dude]

If anyone is curious for their own setup, this is how I wired it.