Help! I Think My Car's Battery Is Defective

One of the most commonly discussed vehicle problems on social media is 12 V battery issues. All modern vehicles use a low-voltage battery to operate the vehicle’s electric system. Yes, even battery-electric, plug-in hybrid-electric, and hybrid-electric vehicles. Electrochemistry used in low-voltage batteries is a mature technology, but with the passing of time, electronics have grown quite a bit in vehicles. Stop-start systems are also now part of the mix. 12 V batteries have never worked harder or run more complex parts of an automobile than today. We’re not going to tell readers they are crazy in this story. Quite the opposite. 

Yes, Stop-Start Does Stress Batteries
I’m neutral on stop/start technology. I own a vehicle with it, and I don't usually disable it. However, the stop-start system has been “implicated,” shall we say, in some battery-related issues in the Ford Bronco Sport. Here’s a snippet from the NHTSA recall letter Ford was forced to mail to every owner:

“The current software for the Body Control Module and Powertrain Control Module is unable to detect — and thus compensate for — the decreasing performance in the life of a 12-volt battery. This could result in the vehicle unable to restart while using the Auto Start-Stop Technology or stalling while coming to a stop at low speeds. This is accompanied by a loss of 12-volt accessories like lights, radio, air conditioning, etc.”

So, if you think that stop-start can have a negative impact on your vehicle, there is now documented proof that it does cause some issues, and they are related to the vehicle’s battery. 

Defective 12 V Batteries Can Catch On Fire
The Volkswagen ID.4 battery-electric vehicle was recently nominated to Car Talks 10 Most Unreliable Vehicles Listing. This vehicle has a list of troubles a mile long. One of the problems is a 12 V battery that can catch on fire. Yes. On Fire. EV folks just despise it when the media reports on anything fire alongside anything EV. Even when true!

In this case, it is actually the 12 V charging cable attached to the battery that is the culprit. VW says in its mandatory NHTSA recall letter that “If left unaddressed, it can present a fire risk.”

Your Automaker Put the Wrong Size 12 V Battery In the Vehicle
Toyota is a brand known for three things, none of which include the term “sexy.” Rather, it is quality, durability, and reliability. That’s what makes this 12 V battery issue so weird. In certain RAV4s, Toyota’s foundation vehicle model, the company installed batteries that were too small. This is no small recall. It affects almost two million total vehicles. 

Here’s what Toyota wrote to customers back in late 2023: 

“Some replacement 12-volt batteries of the size specified for the subject vehicles have smaller top dimensions than others. If a small-top battery is used for replacement and the hold-down clamp is not tightened correctly, the battery could move when the vehicle is driven with forceful turns. The movement could cause the positive battery terminal to contact the hold-down clamp and short circuit, increasing the risk of a fire."

Your Battery Is Indeed Dead, But It’s Not Its Fault
In another case of “Hey, don’t blame the battery for being dead, Ram found itself in a recall situation because its batteries in the Ram 1550 pickup were dying. Here’s what the symptoms and causes are:

“The instrument panel cluster and the radio on your vehicle may not shut off with the ignition in the “OFF” position, which can cause the 12-Volt battery to discharge.“

Your EV Won’t Work Because the 12 Volt Battery Is Dead
If you own a Hyundai, Kia, or Genesis EV, you probably already know this, but the 12 V batteries have been dying and giving owners fits. It turned out that there were two problems. One was related to an overeager Bluetooth app, and another was related to the Integrated Charging Controller Unit (ICCU) fuse. “Two for one battery problems, today only! Get while they’re hot!”

Subaru Battery Issue and Class Action Suit Resolution
Sometimes, automakers don't know why a problem is happening and settle with class action lawyers to help owners get a resolution. A good example of this was the recent Subaru battery class action settlement. Subaru will replace your battery if you fall into one of these models and years:
         2015-2020 Subaru Outback
         2015-2020 Subaru Forester
         2015-2020 Subaru Legacy
         2015-2020 Subaru WRX
         2019-2020 Subaru Ascent
Subaru’s battery-related woes lasted from 2105 until 2023. 

Stealthy Recalls On 12 V Batteries
When Mazda CX-50 owners started to have battery problems, there was no official recall notice to help. However, many dealers have stepped up and replaced the batteries for owners. One owner summarized the situation well by posting, “My battery died two weeks ago. I drive it daily. It is 15 months old with 21500 miles. The dealership replaced the battery, with no cost to me.”

What Do I Do If I Think My 12 V Battery Is Defective?
If your car is having problems with its 12 Volt battery, contact your dealer first and ask if there are any outstanding recalls or Technical Service Bulletins related to the battery or charging issues. If so, let your dealer handle the repair and replacements. If not, you will have to let an independent mechanic help you. Top Tip - Keep your battery receipt. If a recall is later announced you will be eligible for a refund. 

How Can I Easily Replace My Car Battery?
Car Batteries can be replaced by most car owners. The first step is to read your owner’s manual! Find the battery location inside the vehicle. It may be under the hood, under the rear seat, or in the cargo area under a cover. Follow the directions in your manual. Our favorite way to get a new battery is to call AAA. The nation’s oldest and best roadside assistance provider will come to you, test your battery and charging system, and install the battery. We have used this service and found the service outstanding and the prices to be very competitive.

Where Can I Buy A Battery For My Car?
Batteries are sold in almost every conceivable automotive retail location. Dealers have them and can help any brand. Mechanics can get them the same day, and installation is done right. Auto parts stores can help you not only with the part, but many will even help you install the battery. Costco has amazingly low prices and a huge inventory of batteries in stock, but you must be a member.

What's a Fair Price For a Car Battery?

Expect to pay between $200 and $300 for a typical new battery for a car. Always save your old battery to turn in. That price almost always requires that you give back an old one. 

Have you struggled with a battery-related issue in your vehicle? Tell us all about it in the comments section below. Your life experience may benefit fellow motorists. 
 

John Goreham is a credentialed New England Motor Press Association member and expert vehicle tester. John completed an engineering program with a focus on electric vehicles, followed by two decades of work in high-tech, biopharma, and the automotive supply chain before becoming a news contributor. He is a member of the Society of Automotive Engineers (SAE int). In addition to his eleven years of work at Torque News, John has published thousands of articles and reviews at American news outlets. He is known for offering unfiltered opinions on vehicle topics. You can connect with John on Linkedin and follow his work on our X channel. Please note that stories carrying John's by-line are never AI-generated, but he does employ Grammarly grammar and punctuation software when proofreading. 

Images by John Goreham.