Ways to Tell If Your Car Battery Is Dead

There are many reasons this can happen. First, it may simply be old. Experts say the average lifespan of a car battery can reach up to five years in ideal conditions. If your vehicle’s battery is older than that, it may be living out its last days before dying.

Things that shorten a battery’s lifespan

You leave your vehicle’s sound system or interior lights on for a long time.
Your alternator is faulty.
You bought a low-quality battery.
You’re a complete accessory addict.
You’re charging the battery incorrectly.

If the engine doesn’t start when you crank it, or if accessories don’t work or work poorly, the cause can sometimes be corrosion, scaling, or damaged cables on the wires connected to the battery terminals. Make sure this isn’t the case. In the video we’ve shared below, you can see how a damaged and corroded cable affects battery performance.

There are some signs that will tell you whether your battery’s lifespan is over; the trick here is to see whether many, or all, of these signs match your situation. The more of the signs described below that apply to you, the closer your battery is to dying. Here are the signs to watch for:

If your battery drains frequently

Under normal conditions, starting your vehicle will drain the battery slightly, but the alternator (alternator) will recharge it during driving. If you need to charge the battery every 3-5 days or more often, you may suspect the battery is starting to reach the end of its life.

Likewise, if the battery dies within 15-30 minutes while the engine is off and the radio or an accessory is running, this is also one of the signs that the battery’s lifespan is over.

Why doesn’t the battery charge?

If the battery keeps draining even while your vehicle is being driven, this could point to a fault in the alternator, which is responsible for charging the battery.

Your vehicle isn’t charging the battery even though you’re driving it. At first glance, an alternator fault might be suspected, but sometimes corroded (rusted) battery connections can prevent the charging system from filling the battery during driving. In this case, your alternator may not actually be faulty.

Terminal Corrosion

The white/green corrosion layer that forms on battery terminals can block the flow of electricity and cause starting problems.

Average Battery Life

A standard car battery generally lasts between 3-5 years, depending on usage conditions.

Charging System Check

A battery that keeps draining may point to an alternator fault rather than a battery problem.

If You Frequently Have Starting Trouble

When your vehicle’s battery dies, the most obvious sign is that the engine won’t start. Especially in cold weather, it becoming very difficult to start the car after long periods of not running is also a sign.

If you hear nothing when you turn the ignition key

If you hear absolutely nothing when you turn the ignition key, this is a good indication the starter motor isn’t getting power. Combined with other clues, like your headlights not working properly, a dead battery is a fairly likely culprit.

You can hear the starter motor when you turn the ignition key, but the engine won’t start.

You probably already know the sound your vehicle makes when you turn the key. So you may notice subtle changes in that sound that indicate something’s wrong with your vehicle.

Try turning the ignition. Normally you hear the sound of the starter motor running. But when the battery is dead, you’ll only hear a clicking sound.

If Accessories Aren’t Working Properly

The interior lights, dashboard lamp, low-beam headlights, or radio don’t work even though the switch is on when you turn the key. Or they keep turning off on their own.

Check your radio, dashboard lights, automatic doors and windows, headlights, wipers, lights, and speakers. Aren’t they working? These accessories need power — that is, the vehicle’s battery — to operate, so if they don’t work (or work dimmer and weaker than normal), a dead battery may be the culprit.

Focus on your car’s horn first, not the lights. Horns use far more power than your vehicle’s headlights. When the horn doesn’t work, the vehicle’s battery is about to die, or has already died.

If the lights and/or accessories dim or flicker when you press the gas pedal while your vehicle is moving, this is also one of the signs.

If There’s a Rotten Egg Smell Coming From Your Vehicle

Do you smell something bad? Like rotten eggs? That smell is sulfuric acid. Most traditional car batteries are filled with a mixture of sulfuric acid and water. As the battery approaches the end of its life, some of the acid and water evaporate, causing the battery to overheat. This produces that unpleasant smell resembling rotten eggs.

Your Battery Tester Says It’s Dead

If you’re experiencing a few of all these signs, the best and most reliable way to confirm your suspicions is to use a good battery tester and find out whether the battery is dead. This is the most accurate way to know whether your battery still has hope.

Vehicle charging systems normally settle at around 14 volts, and car batteries will generally read around 13 volts when fully and recently charged. Keeping this in mind, normal car batteries are considered “fully discharged” at 10.5 volts, which is only about 80 percent.

If the battery ultimately turns out not to be dead, you might suspect the ignition switch, the solenoid, the starter motor, or things like corroded battery terminals or a loosely connected battery cable. The only way to diagnose this kind of problem is to rule out each of these possibilities one by one.