As an automobile battery nears the top of its lifespan, it starts to lose the power to carry a charge. It becomes unreliable because it delivers subpar performance and fails to satisfy the power demands of your car.
Battery failure are often a real snag if it happens once you least expect it. In case you're trapped in such a fix, determine first the lifespan of your automobile battery before doing anything. You may get to have it checked or buy a replacement one to exchange it.