I decided to purchase a battery analyzer (harbor freight digital one) with winter coming up and wanted to know what real-world experience you have in regards to using the information to replace your battery. The method I've used the 27 years I've owned vehicles is to wait until the day it dies and strands me then take it to be checked and replace it if it's the problem. So I'm trying to be a little more proactive.I thought about just changing them on a schedule, but I've had some batteries last 2years and some 10 years so I'm hoping with the analyzer I can make a more educated guess. In a perfect scenario I would like to replace the battery the day before it died, but obviously that's not realistic. The readings I got are below. *All batteries are Autocraft gold 700Cca batteries as they typically seem like a good deal with promo code from advance Auto. 2006 Camry 4cyl Shows 55% life , 401Cca 2012 Sienna 6cyl Shows 85%life, 572Cca 2003 frontier 4cyl 80% life, 550Cca According to the analyzers manual less than 40%=replace, 40-60%= getting weak consider replacing, 60-80%=workable, 80-100%=good. So by this I should consider replacing the battery in the Camry. For people who have used this type of analyzer do you find their guidelines good, too conservative, or not conservative enough? Would you go ahead and replace the battery in the Camry or wait for it to drop lower?