Do You Have a Dead Car Battery or Alternator Issue?

Driving your car is often a seamless process that takes you where you want to go without a second thought — when things work properly. But if your car doesn’t start normally, it can be frustrating and concerning. The reason? It’s likely a dead car battery or alternator. 

The Top Signs of a Bad Alternator and Dead Battery | Metromile

Is it a dead car battery or alternator? 

If your car is having issues with starting, it could be the battery or alternator. But which one? The good news is there is a relatively easy way to find out. 

First, it’s important to note how the alternator and car battery work together. Your car battery is effectively the power source for many different functions when the vehicle is off, including starting your car. 

Your car alternator helps charge the car battery when the engine is on. These two car parts work hand-in-hand to keep the electricity flowing in your car to make sure things run smoothly. 

If your car doesn’t start at all, you may have a dead battery. If your car starts for a short while, giving you that glimpse of hope that all is fine, but then promptly stops, it’s likely you have an alternator issue. 

To find out whether it’s a dead battery or alternator issue, grab a set of jumper cables and do a little experimenting. 

Jumpstart your car. If you can turn the engine on, but it dies shortly thereafter, your car alternator likely isn’t able to charge the battery. On the other hand, if you jumpstart the car and later on it fails to start on its own, it’s likely a dead battery. 

What are the telltale signs of a bad alternator? 

If you suspect the battery is okay and it might be an issue with the alternator, there are some telltale signs to look out for. 

  • Funny noises. If you’re hearing any clicking sounds when you turn on the car or hear a type of growl or high-pitch sound, it could mean the alternator is shot or on its way out. 
  • Your battery light goes off. It’s natural to think if you see your battery light go off that it must be an issue with the battery. But remember, your alternator helps power the battery, so if things are out of whack, this signal could actually mean trouble with your alternator. 
  • A shift in lights. When your alternator isn’t working properly, you might see a change in the interior lights of your car as well as your headlights. They may start to dim and become even darker, or on the other hand, they may be brighter than usual. 
  • Car accessories aren’t working properly. If your car radio is on the fritz, or your windows are taking forever to roll down, or any other accessory isn’t working as it should. In that case, it could be a sign that your alternator is bad and not providing enough electricity to function properly. 
  • It smells like something is burning. When your alternator isn’t working, it could be burning the rubber drive belt, or there may be hot wires making things smell funny.

How do you know if you have a dead battery? 

If you’re dealing with car trouble, you want to clear things up and understand if it’s the battery or 

alternator. Now that you know the signs of a bad alternator, how do you know if you have a dead battery? 

  • The car battery is several years old. Typically, your car battery can last around four to six years, so if it’s around that time, it might just be time for your car battery to retire and get a new one or see about getting your current one fixed. 
  • The battery smells weird. You should hopefully never smell your car battery, but if you do and it smells like something is rotting, it could be the gasses from the battery. This could be serious, so get it looked at ASAP. 
  • Your dashboard lights or headlights are dim. If your dashboard or headlights aren’t at their full brightness, it could be a telltale sign of a dead battery. 
  • The car is starting slower than usual. It should be relatively easy to start your car and get going. If getting the vehicle started takes more time than usual, it could mean an issue with your battery. 
  • You can see battery corrosion. You might be dealing with a damaged car battery if you’re able to see signs of corrosion. According to Family HandyMan, you might see white powder on your car’s battery terminals, which is the result of a chemical reaction. The site also recommends wearing safety glasses and rubber gloves if dealing with your car battery. 

The bottom line 

If your car isn’t starting normally, you probably have an issue with your battery or alternator. Figuring out if it’s a bad alternator vs bad battery can be done with the signs above. But if you’re still unsure about reading the signs of a bad alternator or dead battery, it doesn’t hurt to get your car looked at by a professional who can help. While having car issues can be a drag, you want to stay safe while on the road. To do that, make sure you have the right car insurance coverage as well. Don’t drive very much? Pay-per-mile insurance may be the right fit for you, as instead of paying a flat rate for miles you don’t drive, you pay based on the miles you drive. Find out a smarter way to do auto insurance with Metromile and get your free quote

Melanie Lockert is a freelance writer, podcast host of the Mental Health and Wealth show, and author of Dear Debt. She’s a cat mom to two jazzy cats, Miles and Thelonious, an amateur boxer, music lover, and needs coffee to function.