It did sit undriven for a while while I was working on the whole big brakes & axle swap, but it sat disconnected with a battery tender on it. It is now a DD. Factor in that reportedly Odysseys have a slightly different ideal charge profile than a typical SLA battery, they want 14.7 VDC instead of the more usual 14.4 VDC.
It's well known in the solar/RV/Marine world that automotive alternator regulators are not all that kind to batteries, and that a better regulator nearly always results in a longer service life from the battery. These regulators and controllers, unlike the automotive regulators, have a minimum of 3 stage charging (Bulk, Adsorption, and float stages) like the better battery chargers have.