weak car battery symptoms

The 3 Most Common Symptoms of a Weak Car Battery

People usually take their car batteries for granted until they have problems starting their vehicles. Then fears of being stranded in the middle of nowhere take center stage as you wonder if the battery is dead or weak. However, a bad battery is not the only thing that can cause your vehicle to not start. Therefore, you want a quick way to know if the problem is truly the battery.

Fortunately, as a car battery weakens it causes a few noticeable changes to your vehicle and its performance. The top 3 most common of these symptoms are:

  • The Battery Dashboard Warning Indicator lights up
  • The headlights and other electrical features fail to work
  • Engine cranking slows down

On their own, these symptoms might mean nothing or something else. However, you should take note if they occur together in any combination. Therefore, by reading further, you will also learn what you can do when you notice your vehicle has them.

What To Do If I Have a Dead Car Battery

A good working battery is key to the smooth operation of any vehicle. It powers all electrical components. It also provides the power to start the car in the first place. Without a good battery, you literally cannot drive anywhere. However, batteries do not last forever.

Once they reach the end of their lifetimes, they start causing havoc to your vehicle’s performance and electrical systems such as windshield wipers and power windows. They can also leave you stranded on the side of the road and a huge repair bill once you get serviced.

Therefore, you need a way to quickly spot a weak battery, and a simple solution in case something goes wrong. They will save you money and unnecessary hours of diagnostics. They will also give you peace of mind during emergencies.

To that end, this article will walk you through the common signs that reveal your car has a bad or weak battery. You can then use the Mach 1 Services app to help you find reliable auto battery repair when you need it.

How Long Does a Car Battery Last?

Most car batteries are sold with life expectancies of 38, 48, and 60 months, though most of the time they can live up to 2-5 years with proper maintenance. As such, you will want to replace the battery before it reaches these recommended service limits.

However, several factors can significantly reduce these lifespans including:

  • Your driving habits
  • Your location
  • The ambient temperature and weather conditions
  • The condition of the charging system
  • Your car’s luxury features and load use

Generally, anything that draws power from the battery will reduce its lifespan, even starting the car. This is due to how batteries work.

What Does a Car Battery Do?

When connected, your car uses the battery to power its various electrical components including:

  • Starter motor – the battery provides the initial power that starts the engine during ignition
  • All lights and indicators – including the dashboard indicators, cabin lights, headlights, and turn signals
  • All electronics – includes power windows and windshield wipers, radio, smart devices, and the system control monitor (or the car’s internal computer)
  • Air conditioner fans and blowers – that keep you cool while driving

How Do I Know When My Car Needs a New Battery?

Because a bad alternator can cause the same issues as a dead battery, you will want to know the difference between them to save yourself some time, money, and a few headaches. Fortunately, routinely checking your battery’s voltage level is a good place to start.

You will need a good multimeter or voltmeter to measure it, but the stored voltage level is directly proportional to the health of the battery. For instance, you should fully recharge it if the voltage ever falls below 12.2 volts. If it goes below 10 volts, consider it dead and replace it as soon as possible.

The 3 Most Common Symptoms of a Weak Car Battery

While routine voltage checks will help, they only help reduce the normal wear on the battery. They do nothing during times of heavy load such as when using the air conditioner during hot summer days. During those moments, the following signs as they are the usual indicators that you have a weak battery.

Symptom 1: Lit Dashboard Warning Indicator

By far, your most important warning that your car has a weak or dead battery is the dashboard warning light. This red battery symbol lights up when you have a battery issue such as a bad charger, alternator, or something internal to the battery. Therefore, if you see it light up, you should check the battery as soon as possible.

However, if you see the Check Engine Light (CEL) turn on as well, you get your car serviced immediately. This sign says the battery is flat and you might not be able to restart the vehicle should you stop. Luckily, this scenario is rare. So, a lit CEL by itself usually means something else is wrong with the engine.

Symptom 2: Weak Headlights and other Electrical Issues

If you ignore the indicator lights, then failing headlights, lights, and electronics are your next sign of impending battery failure. These systems draw power directly from the battery. As such, they are a good indicator of battery performance, especially when the engine is off not and charging it. If they remain bright, the battery is good. If they start to dim or flicker, you have a problem.

Symptom 3: Engine Cranks Slowly

Slow engine cranking is another common sign of a weak battery, but only if it worsens. A lot of things can slow down the cranking such as cold weather. Therefore, the problem is only guaranteed to be the battery if the condition is persistent, or you notice other symptoms. In that case, the battery is about to die and requires immediate attention as you might only have enough power to get off the road.

Other Common Symptoms

The above three symptoms are the most common first signs of a weak battery, but they are not the only ones. Depending on the severity of the problem and the features built into the vehicle, a bead or weak battery can lead to one or more of the following:

  • The engine will not start or clicks when it does
  • Visibly corroded battery terminals or warped battery casing
  • Your car will require frequent jump starts
  • The engine gives off a sulfuric scent
  • Engine misfires or backfires


The battery is the life of your car. If the battery dies, there you can do with your vehicle until you replace it. Luckily, there are a few warning signs that announce the moment when the battery is weak and about to die. Some of them will even leave you with enough power to use our app to flag down one of our technicians during road emergencies.