Toyota and Subaru: 12-Volt Battery Crisis Plagues Their Electric Vehicles

Toyota and Subaru are encountering new challenges in the electric vehicle (EV) market following repeated problems with the 12-volt battery in their bZ4X (Toyota) and Solterra (Subaru) models. Although this issue may seem minor at first glance, it has sparked widespread controversy and led to a class-action lawsuit in the United States, placing significant pressure on both companies to find a quick and effective solution, especially amid increasing competition in the global EV sector.

Background: A Small Battery with a Big Role

Unlike the main high-voltage battery that powers the electric motor, the 12-volt battery in EVs is responsible for operating secondary systems such as windows, seats, air conditioning, radio, lighting, and windshield wipers. It also activates the relay that connects the main battery to the electric drive system. Any failure in this small battery can cause the entire vehicle to stop working, regardless of the main battery’s condition.

Details of the Issue: Repeated Failures and Owner Experiences

According to a lawsuit filed in California, the 12-volt batteries in the 2023 to 2025 Toyota bZ4X and Subaru Solterra models suffer from rapid discharge and repeated failures, even after replacement under warranty. One owner, John Wade, reported encountering the problem twice within less than a year of owning his bZ4X. Warning lights appeared on the dashboard and the vehicle completely shut down, forcing him to call roadside assistance and tow the car to the dealership. After replacing the battery, the problem recurred within less than 2,000 miles, and charging attempts failed to restore function.

Company Response: Temporary Fixes and Ongoing Challenges

So far, Toyota and Subaru’s response has been limited to replacing the faulty batteries under warranty, but complaints indicate that replacement batteries suffer from the same issues. This has led some owners to seek their own solutions, such as purchasing advanced home chargers, but with little success. This raises important questions about the preparedness of both companies to handle first-generation EV problems, especially regarding critical components like the 12-volt battery.

Legal and Brand Image Implications

Toyota and Subaru now face a lawsuit demanding accountability for selling vehicles with known defects without adequate preventive measures. Toyota is expected to formally respond to the lawsuit by July 3. This case raises questions about the companies’ commitment to addressing EV issues in their early stages, particularly when it comes to simple yet vital systems.

Impact on Customer Trust

This issue is a real test of customer trust in Japanese brands known for reliability. As the shift to electric vehicles accelerates, customers expect trouble-free performance, especially in essential systems. Any failure to address these problems adequately could negatively impact Toyota’s and Subaru’s reputations globally and give competitors an opportunity to strengthen their market positions.

Lessons Learned and Future Outlook

This crisis highlights the importance of thoroughly testing every component in electric vehicles, even those that seem simple. It also underscores the need for effective communication channels between companies and customers to detect and resolve issues early and decisively. It is expected that this case will prompt Toyota and Subaru to reassess their secondary battery systems and possibly launch updates or widespread service campaigns if a widespread manufacturing defect is confirmed.

The 12-volt battery problem in Toyota’s bZ4X and Subaru’s Solterra sheds light on the challenges companies face in transitioning to electric vehicles. Although the issue may seem minor compared to complex electric drive technologies, its impact on user experience and customer trust is significant. The final resolution depends on the companies’ response and transparency at a time when competition and innovation in the global EV sector are accelerating rapidly.