Zoos Auto Research has released the "2026 Automotive 12V/48V Low-Voltage Lithium/Sodium Battery Industry Research Report".low-voltage power supply network
Automotive low-voltage power supplies primarily provide power to in-vehicle electrical equipment, including power windows, lighting, illumination, instruments, and various controllers; on the other hand, they supply power to the engine starter motor. For vehicles with different energy types, the role of the 12V/48V onboard power supply varies slightly, mainly regarding whether it needs to power the engine starter motor and its charging method.
Both traditional internal combustion engine (ICE) vehicles and NEVs (New Energy Vehicles) rely on low-voltage batteries. The high load of onboard electronic systems and the realization of safety functions depend on the stable power supply from low-voltage batteries.
In the ICE vehicle sector, each vehicle is equipped with 1-2 low-voltage systems, among which the 12V low-voltage start-stop battery system is standard for start-stop functions and onboard equipment power supply. Meanwhile, some mid-to-high-end automakers, such as BMW and Audi, have further added 48V fuel-saving battery systems to enhance the energy-saving performance and emission compliance capabilities of ICE vehicles.
In the NEV sector, each vehicle is equipped with one low-voltage system with a voltage specification of 12V or 48V. This system is mainly responsible for providing a stable power supply to the traction battery relay switch, advanced driver-assistance systems (ADAS), entertainment equipment, onboard appliances, lighting, and the instrument panel. Overall, the 12V low-voltage battery has four main functions: first, to start the vehicle; second, to serve as a redundant power source after the vehicle is started; third, to provide electrical energy for the vehicle's low-voltage appliances; and fourth, to supply power to the vehicle after it is turned off.
Source: Zoos Auto Research "2026 Automotive 12V/48V Low-Voltage Lithium/Sodium Battery Industry Research Report"
The capacity of traditional 12V lead-acid starting batteries in passenger cars is generally between 0.6 kWh and 1.0 kWh. However, since the usable capacity of lead-acid batteries is typically only 30%–50% of the nominal capacity (as deep discharge can damage the battery), the actual usable energy is far below the theoretical kWh value. Lead-acid batteries are mainly used to start the engine and maintain the power supply for low-voltage appliances in the vehicle. It is not recommended to use high-power appliances for a long time after the engine is turned off to avoid battery depletion.
Estimation of Capacity and Usable Energy of Traditional Automotive Lead-Acid Batteries
Source: Zoos Auto Research "2026 Automotive 12V/48V Low-Voltage Lithium/Sodium Battery Industry Research Report"
Compared to traditional lead-acid start-stop batteries, 12V lithium iron phosphate (LFP) batteries have a volume of 2/3 and a mass of 1/3 of lead-acid batteries with the same capacity. In terms of cycle life: the cycle life of lead-acid start-stop batteries is 400-600 times, while that of LFP batteries is around 2,000 times. Their advantages include long lifespan, small size, light weight, and environmental friendliness without pollution. The current major obstacle is the high cost.
For ICE vehicles, low-cost, safe, and reliable 12V batteries such as AGM/EFB batteries remain unshakeable at present. However, it will become a trend for mid-to-high-end NEV automakers to gradually phase out start-stop lead-acid batteries and switch to low-voltage lithium batteries.
Source: Zoos Auto Research "2026 Automotive 12V/48V Low-Voltage Lithium/Sodium Battery Industry Research Report"
Automotive 12V Low-Voltage Lithium Batteries: Driven by Regulations, Mid-to-High-End NEVs Rapidly Advance the "Replacing Lead-Acid with Lithium Batteries" Plan for 12V Starting Batteries
Starting from July 2023, the new EU Battery Regulation (EU) 2023/1542 is gradually replacing Directive 2006/66/EC. To minimize the harmful environmental impacts of batteries, this new regulation will be implemented simultaneously across all member states.
The new requirements cover the entire lifecycle of lithium batteries for the first time (from the extraction of raw materials to production, design, labeling, traceability, collection, recycling, and repurposing). This regulation applies to all categories of batteries placed on the market or put into service within the EU (excluding special applications such as military, space, and nuclear energy), mainly including the following five types of batteries:
Portable batteries (for non-industrial use, sealed and weighing no more than 5kg)
Starting, Lighting, and Ignition batteries (SLI batteries)
Electric Vehicle batteries (EV batteries)
Light Means of Transport batteries (LMT batteries)
Industrial batteries (batteries designed for industrial use or repurposed for industrial use, or other batteries weighing more than 5kg)
Batteries must comply with the content limits for hazardous substances such as lead, mercury, hexavalent chromium, and cadmium specified in Annex 17 of the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) regulation and the End-of-Life Vehicles (ELV) Directive.
In the new EU Battery Regulation (Regulation (EU) 2023/1542), lead is one of the key controlled hazardous substances. It was already restricted in the EU Battery Directive 2006/66/EC, not just starting with the new regulation, but its use has not been completely banned in a "one-size-fits-all" manner. However, through supporting restrictions such as high proportions of recycled materials requirements, recycling efficiency targets, EU REACH, and the EU ELV Directive, the EU is effectively forcing lead-containing batteries to gradually exit the market. This will have a significant impact on automotive 12V lead-acid starting batteries, gradually promoting the adoption of 12V low-voltage lithium batteries in vehicles.
The European Committee for Electrotechnical Standardization (CENELEC) has introduced relevant standards for 12V low-voltage lithium batteries, namely "EN IEC 63118-1:2024, Secondary lithium-ion cells and batteries for automotive starting, lighting and ignition (SLI) applications and auxiliary purposes - Part 1: General requirements and test methods". IEC 63118-1:2024 specifies general tests and requirements for the performance of secondary lithium batteries with a nominal voltage of 12V permanently installed in non-propulsion road vehicles. This document covers the replacement of non-propulsion secondary batteries permanently installed in road vehicles. Typical applications for batteries within the scope of this document include: power supply for internal combustion engine starting, lighting, stop and start functions, onboard auxiliary equipment, and energy absorption for regenerative braking.
China is also promoting the standardization of 12V low-voltage lithium batteries. The recommended national standard "Secondary lithium-ion cells and batteries for automotive starting, lighting and ignition (SLI) applications and auxiliary purposes - Part 1: General requirements and test methods" has been approved for project initiation, with the draft for review planned to be completed in 2026. The formulation of this standard aims to address the demand for 12V low-voltage lithium battery systems to gradually replace traditional lead-acid batteries under the trend of NEVs and intelligent connected vehicles. Previously, technical standards varied among OEMs. The introduction of this standard will unify industry specifications, ensure product quality, and promote the healthy development of the low-voltage lithium battery industry.
Currently, leading enterprises including CATL, BYD, EVE Energy, Wanxiang A123, and Zhuhai CosMX are all deploying in the 12V lithium battery field. Their weight and volume are significantly reduced compared to lead-acid batteries, and they support lifetime maintenance-free operation. BYD has fully switched the starting batteries of its plug-in hybrid models from lead-acid to LFP batteries; Tesla Model S Plaid, the new Model X, and the domestic Model Y Performance Edition have also replaced their 12V lead-acid batteries with lithium batteries.
In May 2024, BYD announced the comprehensive promotion of the "replacing lead-acid with lithium batteries" plan for 12V starting batteries across its entire DM-i hybrid model lineup, marking that its low-voltage battery technology has entered a stage of full maturity and popularization. Millions of BYD plug-in hybrid models have been equipped with LFP starting batteries.
BYD 12V LFP Starting Battery
Source: Zoos Auto Research "2026 Automotive 12V/48V Low-Voltage Lithium/Sodium Battery Industry Research Report"
SAIC Motor has deployed low-voltage lithium battery management applications and has already integrated them into models such as IM Motors. OEMs have requirements for the domestic substitution of chips in automotive components. For low-voltage lithium battery management applications, there are pre-research needs for the domestic substitution of MCUs (Microcontroller Units), power chips, PMICs (Power Management ICs), half-bridge driver chips, AFEs (Analog Front Ends), etc.
SAICEC Low-Voltage Battery Management (LVBM) Solution:
Lithium battery voltage and current measurement, PCB temperature sampling, lithium battery SOC (State of Charge) calculation, lithium battery SOH (State of Health) calculation, lithium battery charge and discharge management;
Passive cell voltage balancing, power topology operating mode management, overcurrent shutdown protection, self-learning and calibration of algorithms such as SOC and SOH, sleep and wake-up management;
UDS-based diagnostic flashing function, functional safety level ASIL-B, functional safety level of the normally conductive discharge path supporting ASIL-D, high reliability, and high chip domestic substitution rate (nearly 100%).
Control Redundancy: Multi-ECU Redundancy Remains the Mainstream Solution, with Future Development Towards Single-Chip Redundancy
Against the backdrop of lithium resource shortages, given the abundant reserves of sodium resources globally, the substitution of lithium-ion batteries by sodium-ion batteries has gradually become a key focus in NEV industry research. Since sodium batteries have demonstrated excellent potential for performance improvement in terms of low-temperature performance, over-discharge resistance, safety, and environmental friendliness, they are considered one of the potential alternatives to lithium-ion batteries, with broad application prospects.
Compared to lithium batteries, the advantages of sodium batteries lie in:
Abundant resources and low cost: Compared to the scarcity of lithium ions, sodium ions are more abundant in the earth's crust elements, resulting in lower costs, making them a good supplement to lithium-ion batteries. Additionally, both the positive and negative electrodes of sodium batteries use aluminum foil, which can further reduce costs;
Wide temperature adaptability: They maintain a good capacity retention rate within the temperature range of -40℃ to 80℃;
Good fast charging and rate capability: Sodium-ion battery electrolytes at the same concentration have higher ionic conductivity than lithium-ion battery electrolytes. Meanwhile, sodium ions have lower solvation energy in polar solvents, giving them faster kinetic properties and higher conductivity in the electrolyte;
Ultra-long cycle life: Over 20,000 cycles have been achieved, with future goals of over 30,000 cycles;
Safety: Sodium batteries can be stored and transported at zero voltage without transportation safety risks. In the event of a short circuit, they generate less self-heating, eliminating the risk of fire or explosion;
Production: They share similar working principles and material compositions with lithium-ion batteries, allowing production experience and equipment to be partially compatible.
Source: Zoos Auto Research "2026 Automotive 12V/48V Low-Voltage Lithium/Sodium Battery Industry Research Report"
International Standard for Automotive Start-Stop Sodium Batteries Officially Approved for Project Initiation, Led by Chinese Enterprises. On October 10, 2025, the IEC/TC21 international standard discussion meeting for new proposals on sodium-ion batteries was held in Wuhan, Hubei Province. This seminar focused on the new international standard proposal "12V sodium-ion batteries for automotive start-stop applications - Part 1: General requirements and test methods" jointly proposed by Camel Group, Tianneng Sodium, and Jujiang Group. This is also the first proposal for a 12V sodium-ion battery standard for automotive start-stop applications led by China. The proposal was recently voted on by member countries of the International Electrotechnical Commission Technical Committee on Secondary Cells and Batteries (IEC/TC21), receiving unanimous approval from all 17 voting P-members (Participating members) and was officially approved for project initiation.
Currently, sodium batteries have achieved batch applications in energy storage power stations, two-wheeled electric vehicles, automotive start-stop power supplies, and other fields, and are exploring "lithium-sodium hybrid" solutions mixed with lithium batteries; the EU still plans to maintain ICE vehicle sales in the long term, which will lead to a continuous increase in the penetration rate of start-stop systems, accelerating the global layout of sodium batteries.
In the low-voltage power supply field, sodium batteries will compete fiercely with LFP batteries. In 2025, the average price of sodium battery cells is 0.52 RMB/Wh. Referring to the development experience of lithium batteries, future cost reductions of 50% will come from material system optimization, and 30% from scaled production; with the large-scale release of production capacity starting in 2026, the price of sodium batteries is expected to drop by another 30% within two years. By 2027, the cost in some scenarios may be lower than that of LFP batteries. It is estimated to drop to 0.25 RMB/Wh by 2030.
Cost Comparison of Various Automotive Battery Cells
Source: Zoos Auto Research "2026 Automotive 12V/48V Low-Voltage Lithium/Sodium Battery Industry Research Report"
In May 2025, Camel Group's power-type 46145 large cylindrical sodium battery was unveiled. The product can achieve 10C continuous discharge, has a capacity of 18Ah, a cycle life of over 3,000 times, and an operating temperature of -40℃ to +65℃. It is mainly targeted at start-stop power supplies and other fields, demonstrating good high-rate discharge performance, long cycle life, and wide temperature adaptability. Meanwhile, the delivery of Chery's 12V 40Ah cylindrical sodium battery samples and the freezing of the 24V 170Ah solution mark that Camel Group's sodium battery technology has officially moved from laboratory R&D to the stage of engineering application.
In MHEVs (Mild Hybrid Electric Vehicles), the main low-voltage rail powering the E/E (Electrical/Electronic) system is still 12V, requiring the configuration of large bidirectional converters between the 48V and 12V voltage rails, which significantly increases the cost burden. However, HEVs (Hybrid Electric Vehicles), PHEVs (Plug-in Hybrid Electric Vehicles), and BEVs (Battery Electric Vehicles) can use high-voltage batteries to create a 48V low-voltage rail to power the entire E/E system.
Automotive 48V Lithium Batteries Can Be Applied in 48V MHEVs, PHEVs, and BEVs
Especially in today's electric and smart vehicles, there are increasingly more power loads ranging from hundreds of watts to several kilowatts: from high-power air conditioners and heated seats to ADAS domain controllers and computing platforms. The 12V system not only has a massive current but also requires thick and heavy wiring harnesses, leading to a surge in power consumption and costs. The emergence of 48V aims to reduce the current to one-quarter at the same power, making the wiring harnesses thinner, lighter, and reducing losses. According to the principle of P=UI, the reduction in current brings two direct benefits: improved energy efficiency and reduced costs.
NEVs (BEVs) will further introduce 48V PND (Power Network Distribution / Low-Voltage Power Supply Network), integrating it with the zonal architecture to ensure these increased power load requirements.
NEV 48V PND (Low-Voltage Power Supply Network) Architecture Topology
Source: STMicroelectronics
Regulations are one of the key factors driving 48V towards large-scale adoption. As the subsequent regulatory standard for 48V, ISO 25769 is expected to be released around 2028. This standard is expected to lower the maximum voltage requirements and transient voltage durations, making it more adaptable to the working environment requirements of 48V domain controllers. The establishment of regulatory standards will also rapidly promote the maturity of 48V architecture solutions.
Full name of the standard: ISO 25769 "Road vehicles - Electrical and electronic systems and components - Electrical requirements and tests for 12V, 24V, and 48V supply voltages".
Core objective: To establish unified electrical requirements and test methods for automotive electrical/electronic systems at the three voltage levels of 12V, 24V, and 48V, replacing and upgrading existing fragmented standards.
Scope of application: Covers 12V/24V/48V systems and their components powered by generators, alternators, or DC/DC converters, including wiring harnesses, connectors, controllers, actuators, etc.
This standard is currently at the Working Draft (WD) stage of the international standard. Key time nodes: Mid-to-late 2026: Planned submission of the Committee Draft (CD); Around 2028: Expected official release.
Source: Zoos Auto Research "2026 Automotive 12V/48V Low-Voltage Lithium/Sodium Battery Industry Research Report"
To support the work of the Environmental Conditions Working Group (hereinafter referred to as ISO/TC22/SC32/WG2) under the Subcommittee on Electrical and Electronic Components and General Systems of the Road Vehicles Committee of the International Organization for Standardization, the 31st meeting of ISO/TC22/SC32/WG2 was successfully held in Tianjin from January 26 to 30, 2026. The meeting focused on discussing the feedback from various countries during the WD stage of the ISO/WD 25769 series of standards "Road vehicles - Electrical and electronic systems and components - Electrical requirements and tests for 12V, 24V, and 48V supply voltages". The ISO/WD 25769 series of standards is divided into three parts, of which:
"Part 2: Systems and components powered by DC/DC converters" is jointly led by China and Germany;
"Part 1: General provisions" and "Part 3: Systems and components powered by generators or alternators" are led by Sweden;
According to the work plan, the three international standards will be submitted to the CD stage in mid-to-late 2026 and officially released in 2028.
Currently, on a global scale, only Tesla has achieved large-scale mass production of the 48V PND (low-voltage power supply network) at this stage. The auxiliary battery system of Tesla's all-electric pickup truck Cybertruck has also been upgraded from the original 12V to 48V.
The Cybertruck 48V low-voltage lithium battery is arranged in the middle area of the front trunk, fixed to the vehicle with two bolts, and the torque of the bolts is 8Nm.
The 48V lithium battery is provided by Zhuhai CosMX. The 48V power supply uses 4Ah cells, configured in a 1p13s pack, with a rated voltage of 41.6V. It can be deduced that a single cell is 3.2V, indicating that it is an LFP cell.
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