Most car batteries last around four years, but they vary between about two and five years' lifespan. The lifespan of any given battery depends on the brand and how the driver strains it when driving, but there are ways to get the most out of a car battery.
When possible, avoid frequent stops. When you drive the car, the motion of the wheels activates the alternator, which sends charge to the battery. Frequent stops therefore prevent the battery from getting a full charge.
It's also possible to place an insulation blanket around the battery if there's space under the hood. This device keeps the battery at a steady temperature, which is useful because excessive heat or cold can drain battery life.