The best way to know when to replace an automobile battery is to have it tested at an automotive repair shop or auto parts store. This process should be a part of the routine maintenance of the vehicle at every oil change, according to HowStuffWorks. If the vehicle requires jump starting, it is best to drive to a shop that offers battery testing and have technicians check the battery.
Jump starting is an emergency service to rescue a vehicle with a dead battery. The process uses the power from another battery connected in parallel with the vehicle's battery to turn the starter and start the car. In many instances, the alternator of the vehicle then recharges the battery, and the owner experiences no further problems.
Lead-acid batteries have a lifespan of approximately five years. At the four plus year range, a dead battery often indicates a need for replacement. At this point, the battery is no longer able to hold the charge supplied by the alternator, requiring replacement.
If the routine maintenance test reveals the battery is getting weak, it is time for a replacement. A battery that has been providing a slower than normal start during moderate temperatures is no longer able to start the car the first day the temperatures drop below freezing, stranding the driver.