All I can add is my personal experience for what it's worth.
My wife had a '95 Saturn that needed a new battery about every 12 months. The battery was enclosed in a plastic box. After going through several batteries, on a hunch I did not replace the plastic box when installing a new battery. The battery lasted at least three years this way. From then on, no box = much longer battery life.

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You're shy a few manners.