Today I go to the wholesale club 18 miles away. Car started and ran fine. I got home, an hour later when I tried to start the car I would hear one click and that is it. I first checked the battery with a multimeter and it read 12.1 volts and the green light was on the meter indicating a good battery. Then I used a battery tester which also indicated a good battery at about 68 percent. The ccas on the meter was reading 435 out of 700 cca s that the battery was rated at. Finally I used a jump pack which was barely alive and was able to get the car started. The alternator was reading 14.1-14.3 volts. Is the battery dead. It is a little bit over 3.5 years old, it's an interstate from Costco. I noticed the same thing happened to the battery from the Mazda dealer when he replaced the original Panasonic battery that came with the car. The Mazda replacement lasted only 3 years. Is this the new norm for car batteries. All input would be greatly appreciated. I am trying to find out if this is a battery issue or maybe something else.