The average life span of a battery is 4 years if it’s taken care of. It is very possible for the battery to be defective but still starts the car. Generally, one of the cells shorts internally which significantly reduces the reserve capacity. That means if you were to leave the lights or radio on while the engine is not running the battery will run down much sooner and not start the car. We can easily test for this now with modern battery testers. In addition to not starting the car, a weak battery can damage the alternator by overworking it.
We test your battery at our auto repair shop every time we do an oil change service. This helps to catch a weak battery before you become stranded. Sacramento can get very hot or very cold which are both hard on batteries.
One other thing to remember is if you always drive short distances your battery may not recharge completely. An undercharged battery will have a much shorter lifespan. Battery manufacturers recommend putting the battery on a charger overnight about once per month. There are some very inexpensive and easy to use battery chargers available now.