Everything is born or created with an expiration date. Living things die, non-living things wear out, and that can of corn on the cob you’ve had in the back of your pantry since the Clinton administration isn’t bulging because it’s happy to see you.

All of this is not to say that you can’t hold back the tidal wave of entropy for a while. Eating right and exercising can help you live longer and healthier, and in the same way, proper care and maintenance of your car battery can help it last longer than it otherwise would.

Of course, that’s a double-edged sword. In the same way that an actuary can tell you exactly how many minutes an extra puff on that cigarette will shorten your life, every time you discharge a car battery, you shorten its operational life in a way that is simply impossible to undo. It’s simply a function of the science of how car batteries work.

The operational life of a battery is usually expressed in duty cycles. This term is used for all types of batteries, so there is no concrete definition for every application. For example, some batteries are designed to be fully discharged, while others are designed to always have a certain level of charge.