For the first time in it's life, the G8 didn't start on the first try. It sounded really weak even though I've driven the cat as recently as Sunday.
I'm off to buy a new battery - hearing the stories here there's no sense trying to rejuvenate a dying battery.
later
$144 - 3 year replacement - 7 year prorated warranty - in stock at my local AutoZone - now I just have to change it out