Update - the engine cut-off switch worked. After returning to the car after leaving it for three months I unlocked the door, popped the hood, installed and turned the cutoff key and it started right up.
Thanks for this; good to hear. Yeah I think a disconnected battery has MUCH better longevity, especially if it was in good shape at the outset.
I have batteries that are not on battery chargers all winter and they hardly drop at all. I have two large lawnmowers and they have no parasitic draw and one car that has a switch on it and it did drain some because I forgot to open the switch. I made a few homemade voltage testers that are attached to most of my batteries so all I have to do is touch a button to check voltage. My wife won't leave battery chargers on anything because she is afraid of fire. I own about five battery chargers of different types.
A healthy battery that is fully charged should not drop much over at least 6 months. Being cold helps. There is something to be said for NOT keeping a marginal battery alive just a little bit longer with the use of a tender.
There are a LOT of things in the average home that are more likely to start a fire than a small battery maintainer. BUT.....I am NOT suggesting that you try to tell your wife that.....no, no, NO.
