Of course, some CCA loss is normal over time. But at what point do you replace the battery? The Sienna battery tested at 501 out of 700 CCA, a loss of 29.5%. It's a 4 year old Autocraft gold. And the Buick battery tested at 499 out of 660 CCA, a loss of 24.4%. It's a 2.5 year old AC Delco Silver. (Both are JCI batteries.) Would you guys replace them or wait?