A new lawsuit claims that the 12-volt battery in the two EV models from Toyota and Subaru is prone to premature failure
June 10, 2025 at 10:33
- The plaintiff says his Toyota bZ4X has already had two 12-volt battery replacements.
- The 12V battery is used for the HVAC, radio, lights, and other important functions.
It hasn’t been an easy ride for Toyota and Subaru’s first major foray into the EV market. The Toyota bZ4X and Subaru Solterra stand out for their unconventional styling, but unfortunately, not for reasons that win over buyers. Now, Toyota has been hit with a lawsuit in the US that claims the vehicles have 12-volt batteries prone to premature failure, and that the carmaker knew about the problem before it began selling the vehicles.
Filed in California, the class action lawsuit targets 2023 to 2025 model year Toyota bZ4X and Subaru Solterra models. According to the complaint, the 12-volt batteries in these EVs are prone to draining quickly and dying altogether. Although the vehicles are still under warranty and dealers have reportedly been replacing the batteries, the lawsuit alleges that replacements are just as unreliable.
Read: Toyota Kills bZ4X To Welcome New bZ
As with over EVs, the 12-volt battery in question isn’t the one powering the car’s electric motors. It handles secondary systems like the windows, seats, HVAC fans, radio, lights, and wipers. It’s also believed to activate a relay that connects the main battery pack to the electric drivetrain. In other words, it may be small, but when it fails, the car is effectively dead in the water.
Just a single plaintiff has been named in the lawsuit: John Wade. He bought a 2023Toyota bZ4X in March 2023 and says he began experiencing issues within weeks. According to the filing, a series of warning lights lit up the dashboard before the vehicle completely shut down, requiring roadside assistance just to get moving again. Less than 2,000 miles later, the 12-volt battery failed a second time. This time, even a jumpstart couldn’t revive it.
Wade claims he was forced to tow his EV to a nearby Toyota dealership, which replaced the 12-volt battery. In December 2024, this replacement battery died. While attempting to diagnose the problem on his own, Wade paid $4,800 for a Level 2 home charger as he believed the issues may have stemmed from “not using a sufficient EV battery charger.”
Toyota now has until July 3 to officially respond to the lawsuit. For both Toyota and Subaru, the case raises questions about how well early EV issues are being addressed, particularly when they involve something as basic as the 12-volt battery system.
