Last week I was at someones house and was going to pull their car out of the garage. When I turned the ignition key, the engine began to turn over and then the starter solenoid clicked for a few seconds and then nothing from the engine. How could the battery be dead since it’s less than 6 months old? I popped the hood and started looking at the battery. The battery cables were jiggled and both were a little loose on the terminals. This was probably the issue and once I tightened them and then charged the battery, it started. Later I discovered from the owner that the headlights are on a timer and for a few minutes after the engine stops they stay on. This probably contributed to the dead battery. The car has started every time it for almost two weeks so the loose battery cables were the problem.