Summary
- Modern EV traction batteries are showing high reliability, with very few failures reported
- EVs still require 12-volt batteries to power low-voltage electronics and systems
- Issues with 12-volt batteries have been reported in EV models like the Hyundai Ioniq 5, Kia EV6, Rivian R1S, and R1T
- EVs use DC-to-DC converters to manage 12-volt battery charging, with different strategies for power management
- Automakers are learning and improving the management of 12-volt batteries in EVs, with future models likely to have better reliability
Article
The Unfortunate Reality of Electric Vehicle 12-Volt Batteries
Many consumers have expressed concern about the long-term reliability of electric vehicle batteries, but the reality is that modern EV traction batteries are proving to be quite reliable. However, it’s not the massive drive batteries in EVs that are causing issues, but rather the humble 12-volt batteries. While traditional cars use a 12-volt lead-acid battery to power the electronics and start the vehicle, EVs also rely on 12-volt batteries for similar functions, such as powering low-voltage electronics and passive entry systems.
The Misconceptions Surrounding EV Batteries
There are misconceptions about the reliability of EV batteries, with many assuming that the massive main battery in an EV should never fail. However, data from Consumer Reports shows that 12-volt battery issues are common trouble spots for EVs from various manufacturers, including Hyundai, Kia, and Rivian. These issues can lead to unexpected breakdowns and in some cases, recalls due to problems with the 12-volt charging system. It’s essential to understand how EVs charge and use their 12-volt batteries to grasp the potential issues.
Understanding How EV 12-Volt Systems Work
EVs typically use a DC-to-DC converter to step down high voltage from the main battery to charge the 12-volt battery. There are two basic strategies for managing this system, with some vehicles using a simple approach to charge the low-voltage battery when the vehicle is on. However, some designs may deplete the 12-volt battery due to constant power demands, leading to premature failure. Issues with 12-volt batteries have been reported in various EV models, indicating a need for better management of these systems.
Why EV 12-Volt Batteries Fail
Certain EVs have experienced issues with 12-volt batteries due to design flaws or overvoltage problems that damage the charging control unit. This can lead to a gradual loss of drive power and increase the risk of crashing, prompting recalls from manufacturers. While some automakers have made improvements to their charging systems to prevent future failures, there is still a need for better reliability in 12-volt batteries across the industry.
Is This a Long-Term Issue for EVs?
While some older EV models had occasional issues with 12-volt batteries, newer models have shown improvements in reliability. Automakers are working on innovative solutions, such as trickle-charging approaches, to prevent premature failure of 12-volt batteries. The growing trend of starter battery issues in the automotive industry is not specific to EVs, but the increased power demands in modern vehicles are putting more strain on 12-volt batteries.
The Future of EV 12-Volt Batteries
Despite the challenges with 12-volt batteries, automakers are making progress in addressing these issues. Dual-battery setups and deep-cycle batteries are being considered to better suit the demands of EVs, and some manufacturers are moving towards 48-volt systems for improved reliability. As the industry gains more experience with EV technology, we can expect to see better management of 12-volt batteries and a reduction in related issues. The key is to continue learning and adapting to the unique demands of electric vehicles.
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