BONUS: The Tech Sheet (Pt1) - Why Do Cutting Edge EVs Have A 12 Volt Battery?

EV News Daily - Technology and Business of EVs

Martyn Lee

Technology, Leisure, Automotive, Business

4.8 • 749 Ratings

🗓️ 23 September 2025

⏱️ 36 minutes

🔗️ Recording | iTunes | RSS

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Summary

WHY DO CUTTING EDGE EVS STILL HAVE A 12 VOLT BATTERY?

Welcome back to EV News Daily, welcome The Tech Sheet, the name we give to special bonus episodes which explain the tech behind EVs.

Despite the advances in electric vehicle technology, from massive lithium-ion battery packs to sophisticated power management systems, virtually every modern electric vehicle still carries what appears to be an automotive relic: the humble 12-volt lead-acid battery.

This seemingly anachronistic component, dating back to automotive conventions established in the 1950s, continues to play a critical role in even the most advanced electric vehicles. The persistence of 12V systems in cutting-edge EVs represents a fascinating intersection of legacy engineering, practical necessity, safety requirements, and economic considerations that have proven remarkably resistant to disruption.

The recent introduction of Tesla's Cybertruck with its groundbreaking 48-volt electrical architecture has reignited industry discussions about whether the time has finally come to abandon the decades-old 12V standard. Tesla's decision to share its 48V implementation documentation with other automakers has created both opportunity and controversy, raising fundamental questions about the future of automotive electrical systems. Yet two years after the Cybertruck's launch, the industry has largely remained committed to traditional 12V architectures, revealing deep-seated challenges that extend far beyond simple technical preferences.

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6-Volt Era (1920s–1950s): Early cars used simple 6-volt systems for lighting, ignition, and basic accessories.

Electric Starter Innovation (1912): Cadillac’s electric starter replaced hazardous hand cranking, creating the first real demand for onboard batteries.

Primitive Battery Tech: Early lead-acid batteries were heavy, maintenance-intensive, but crucially rechargeable, forming the backbone of automotive electrification.

Transition to 12 Volts (1953–1956): GM pioneered the switch to 12 volts to handle more powerful engines, advanced lighting, and growing accessory loads.

Efficiency of Higher Voltage: Doubling voltage reduced current needs, allowing thinner wiring, cost savings in copper, and improved reliability.

Industry Standardization: By 1956, nearly all US automakers adopted 12 volts, though some European brands (e.g., VW) stuck with 6 volts into the 1960s.

Failed 42-Volt Push (1990s–2000s): Attempts to move to 42 volts collapsed due to entrenched 12-volt supply chains, high transition costs, and improvements in electronics that stretched 12-volt capacity.

Dual Systems in EVs: Modern EVs use high-voltage packs (400–800V) for propulsion plus a separate 12-volt system for safe, standardized accessory power.

Critical Role of 12 Volts in EVs: Powers ECUs, startup systems, safety features, and even contactors that enable the high-voltage battery—failure immobilizes the car.

Manufacturing & Service Dependence: Wiring harness complexity, global supply chains, technician training, and standardized safety/service procedures all lock in 12-volt dominance.

Economic & Regulatory Inertia: Supplier ecosystems, cost-benefit barriers, and established safety frameworks have long prevented alternative low-voltage standards from taking over.

Tesla’s 48-Volt Revolution (2023, Cybertruck): First production vehicle to adopt full 48-volt architecture; reduces current loads, wiring weight, and improves efficiency but required custom components outside traditional supplier chains.

Transcript

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0:00.0	A Better Help ad.
0:02.3	Lewis Capaldi partnered with Better Help to get word out about how important therapy can be.
0:07.6	I struggle most weeks to get up, get myself up and ready and go to therapy or whatever.
0:13.0	Even like to open the laptop to talk to, my therapist sometimes could be really difficult.
0:17.4	But I do it because I realize how important it is for me to continue to feel good.
0:22.0	Because I felt the best I've felt in a long time through therapy.
0:25.6	Learn more about online therapy at betterhelp.com.
0:29.5	A better help ad.
0:31.5	Lewis Capaldi partnered with BetterHelp to get word out about how important therapy can be.
0:36.8	I struggle most weeks to get up, get myself up and ready and go to therapy or whatever.
0:42.2	Even like to open the laptop to talk to, my therapist sometimes could be really difficult.
0:46.6	But I do it because I realise how important it is for me to continue to feel good.
0:51.0	I felt the best I've felt in a long time through therapy.
0:54.8	Learn more about online therapy at betterhelp.com.
0:58.4	Welcome back to Evie News Daily. Welcome to The TechSheet, the name that I give to special
1:02.5	bonus episodes, which explain the tech behind EVs. You'll have seen in your podcast feed
1:06.8	some bonus shows, the other ones I'm going to call the Spec sheet where we look at the
1:10.5	specifications of a new electric vehicle. Well, today I'm going to call the spec sheet where we look at the specifications of a new electric vehicle. Well, today, I'm going to ask the question why the car industry still has 12-volt batteries in cutting-edge EVs. And we might make this a two-parter, actually. There's a lot to get into because Tesla's trying to move the industry forward once again, as they've done many times in the past, but at the moment, well, the industry isn't biting on this one.
1:30.7	Despite the advances in electric vehicle technology, from massive lithium-mine battery packs to sophisticated power management systems, virtually every modern electric vehicle still carries what appears to be an automotive relic from the past,
1:46.1	the humble 12-volt lead acid battery. This seemingly anachronistic component dating back to
1:54.3	automotive conventions of the past back in the 1950s continues to play a critical role in
2:00.7	even the most advanced electric vehicles.
	...

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