Click,Clickety, goes the Starter???

A few more things, a battery that just sits for "any" length of time is not really a good thing. I would think a few weeks is fine however. Over time the cells have time to build up sulfates on the plates...thus, will still show a good charge (12V), but a great loss in cranking amps; and even though you jump it and it shows a good charge from your ALT does not mean your batterys fine. After you try out another battery to confirm, and if all seem good; take your back your battery for a replacement if still under warrenty. Tell them it shows voltage but won't crank for any length of time.
Good Luck, Let us know your results. :salut: