Wrench, what's the procedure to test a battery and know when it's time to replace? My main battery is over 2 years old now, and the little one....who knows? All it does is power the depth-finder and lights.
BTW, my old car (you know which one) has a battery that is probably 10-12 years old now, and tires that may be close to 18. I think this is the year to replace both.