Way back in the start of this, I mentioned a marine switch...
These look a little like what I meant, but also look a little small
The kind I was talking about was a choice:
Bat One, OR
Bat Two, OR
Both...
You do NOT throw the switch when things are powered up...
If I was actually doing this myself, I'd do a lot more investigation
than just asking questions on a list...
Disclaimer:
I have switched automotive elecrical systems from generators to alternators,
(including the physical mounting, VoltageRegulator, and all wires)
but never paid much attention adding a second battery...
Rick Glazier
From: "Al Anger"
Two car Batteries
get a couple of these:
http://www.jamestowndistributors.com/userportal/show_product.do?pid=2768&familyName=Marine+Battery+Spare+Key+Mini+Switch&history=8jejesn1%7Ctop_category%7Cpage%7EGRID%5EcategoryName%7EElectrical%5EcategoryId%7E93%40x636zz1t%7Cother%7Crefine%7E1%5Epage%7EGRID%5EcategoryName%7EElectrical%2BSwitches%5EcategoryId%7E183
