Though car battery problems can be frustrating, a little knowledge goes a long way when it comes to observing symptoms and diagnosing the issue. Even people who aren't the mechanical type can take a logical approach to eliminating what is not the problem in order to settle on what is. The first thing to do is put aside your frustration for the moment and figure out exactly what the symptoms are.
When your car won't start and you suspect the problem might be the battery, the first thing to do is turn on the headlights. If the lights flick on to their usual brightness and don't dim over the course of a few minutes, your battery is just fine. No need to replace it; look elsewhere for the problem. If, however, the headlight intensity fades quickly or never reaches full brightness, it means your battery is low on voltage.
Presumably, we all know what a running car sounds like. If you turn the key in the ignition and hear absolutely nothing, no engine turning over or anything, there's a chance the battery is the problem. Check the voltage; it's probably low. There's a possibility that a silent car could be the result of a starter problem, but the voltage check will allow you to trace the issue to either the battery or starter.
If you turn the key and hear a prolonged clicking sound, it means the ignition is working to turn the engine over but is finding no charge in the battery to help out. That clicking is the sound of the ignition trying over and over to do its job, and usually means you have a dead battery.
Another iteration of the dead-battery problem is the sluggish start. You've probably heard one before: turn the key and the engine turns over ever so slowly. Maybe it finally catches and starts and maybe it doesn't. This is almost certainly a sign of a dying battery that doesn't have many successful turnovers left in it. In fact, it may not start the next time you ask it to. Unless you prefer being stranded, go straight to the auto parts store and have the battery tested, even if it makes you late for work. Otherwise, chances are good you'll never leave work at the end of the day. Most parts stores will test your battery for you right there and, luckily, sell you one, and probably install it also. It takes only about five minutes.
