3x3 Institute

Automotive conversion from 12v to 48v

December 7, 2023

A primary interest of mine is that use of AI tools and techniques to improve engineering. With today’s discussion (article “Tesla shares 48V architecture with other automakers to move the industry”) about the conversion of automotive systems from 12v to 48v, I thought it would present an interesting example problem to explore.

Asking ChatGPT4 to compare 12V and 48V automotive systems, it responded with the following:

Aspect 12V System 48V System
Power Capacity and Efficiency Lower power capacity, less efficient for high power demands Higher power capacity, more efficient for advanced electronics
Mild Hybrid Technology Not suitable for mild hybrid applications Suitable for mild hybrid technology, enhancing fuel efficiency
Weight and Space Savings Heavier and larger wiring due to higher current for same power Lighter and more compact wiring due to lower current for same power
Cost Implications Generally lower cost for standard applications Higher initial cost, but potential long-term efficiency gains
Compatibility and Integration Widely compatible with standard automotive electronics Requires converters or dual systems for 12V components
Safety Considerations Standard safety measures sufficient due to lower voltage Additional safety measures required but still considered low-voltage

Advantages and Disadvantages of 48V Systems

Asking ChatGPT4 to evaluate the change from a 12V to 48V system.

Conventional Internal Combustion Engine (ICE) Vehicles

Asked to specify advantages / disadvantages for conventional ICE vehicles, it responded with the following:

Aspect Advantages of 48V System Disadvantages of 48V System
Enhanced Electrical Features Supports more powerful electrical components and advanced features -
Improved Start-Stop System Smoother and more efficient start-stop system -
Potential for Light Electrification Allows for mild electrification features improving efficiency -
Reduced Wiring Weight and Complexity Thinner wiring for same power transmission, leading to weight savings -
Higher Cost - More expensive than traditional 12V system
Complexity and Maintenance - More complex design, potentially higher maintenance costs
Compatibility Issues - Possible compatibility issues with standard 12V accessories
Limited Performance Improvement - Limited performance improvements without hybrid technology
Safety Considerations - May require additional safety measures

Hybrid Vehicles

Asking it to specify advantages / disadvantages for ICE / electric hybrid vehicles, it responded with the following:

Aspect Advantages of 48V System in Hybrid Disadvantages of 48V System in Hybrid
Electrical Power for Hybrid Functions Adequate power for electric motor assisting ICE -
Fuel Efficiency Improved fuel efficiency due to electric assistance -
Regenerative Braking More effective regenerative braking system -
Performance Enhancement Enhanced acceleration and overall performance -
Compatibility with Advanced Electronics Supports sophisticated electronic systems and features -
Complexity and Cost - Higher initial cost and system complexity
Maintenance Requirements - May require specialized maintenance
Safety and Handling Potentially improved handling due to better weight distribution Additional safety considerations due to higher voltage

Electric Vehicles

Asking it to specify advantages / disadvantages for electric vehicles, it responded with the following:

Aspect Advantages of 48V System in Electric Vehicle Disadvantages of 48V System in Electric Vehicle
Drive Train Efficiency More efficient power delivery for electric drive train -
Power Delivery for Vehicle Systems Adequate power for advanced vehicle systems and features -
Battery Management and Charging Improved battery management and faster charging capabilities -
Vehicle Weight and Design Potential weight savings in electrical components -
Cost of Production - Higher production costs compared to 12V systems
Maintenance and Reliability - Potentially more complex systems, requiring specialized maintenance
Compatibility with High-Power Electronics Better compatibility with high-power electronics and features -
Safety Standards - Higher safety standards required due to increased voltage

Design consquences from 12V to 48V conversion

Design Aspect Consequences of Moving to 48V
Wiring and Connectors Adapted for higher voltage, can be thinner for same power, redesigned connectors
Battery and Charging System Requires batteries and charging systems compatible with 48V
Power Distribution and Control Updated power distribution units and control systems for higher voltage
Voltage Conversion DC/DC converters needed for existing 12V components
Heat Management Adjusted cooling and thermal management systems for different heat patterns
Safety Measures Enhanced safety protocols and insulation for higher voltage
Component Compatibility Redesign or adaptation of electrical components for 48V compatibility
Electronic Control Units (ECUs) Upgrades or redesigns of ECUs for 48V system operation
Weight Distribution Adjustments in vehicle design for optimal balance and handling
Cost Implications Increased production and maintenance costs due to complexity and new tech

Component changes when converting from 12V to 48V

Component Impact of Moving to 48V
Battery Requires a battery capable of storing and delivering energy at 48V
Alternator/Generator Needs to handle higher voltage and efficiently charge the 48V battery
Wiring Harness Adapted for higher voltage, wires can be thinner for the same power
DC/DC Converter Needed to step down voltage from 48V to 12V for certain components
Electronic Control Units (ECUs) May need upgrades or redesigns for higher voltage operation
Starter Motor Adaptation required for compatibility with 48V system
Regenerative Braking System Can be more effective with 48V, requiring adjustments/enhancements
Electric Power Assisted Steering (EPAS) Improved performance with 48V, may need adaptation or upgrade
Air Conditioning and Thermal Management Upgraded to electrical versions for better efficiency with 48V
Electric Turbocharger/Supercharger More effective implementation with a 48V system
Safety Systems Adjustments in insulation, circuit breakers, and electrical safety
On-board Sensors and ADAS Modifications for compatibility with higher voltage and power
Infotainment and Advanced Electronic Systems Adjustments for higher voltage power supply and distribution

Supply chain effects

The shift from 12V to 48V systems in vehicles has several implications for the automotive supply chain. These effects can be wide-ranging, impacting various stages from manufacturing to after-market services:

  1. Component Sourcing and Manufacturing: The need for new or modified components (like 48V-compatible batteries, wiring, ECUs, etc.) means suppliers must adjust their manufacturing processes. This could involve sourcing new materials, investing in new manufacturing technologies, and retraining staff.

  2. Research and Development (R&D): There’s an increased demand for R&D in developing components optimized for 48V systems. Suppliers need to innovate to meet the new technical requirements, which could lead to collaborations or partnerships within the industry.

  3. Supply Chain Diversification: The change may necessitate diversifying the supply chain to include new vendors specializing in high-voltage systems and components, potentially affecting long-standing relationships with existing suppliers.

  4. Quality Control and Safety Standards: Higher voltage systems require stricter quality control and adherence to safety standards. Suppliers must ensure that their products meet these elevated requirements, which might require additional testing and certification processes.

  5. Cost Implications: The transition to 48V systems might initially increase costs due to the development of new technologies and the scaling of production. These costs can affect the entire supply chain, from raw material suppliers to OEMs.

  6. Training and Skills Development: There’s a need for upskilling and training across the supply chain. This includes engineers and designers focusing on 48V technology, as well as technicians and service personnel who will handle these vehicles.

  7. Logistics and Inventory Management: Automotive manufacturers and suppliers may need to adjust their logistics and inventory strategies to accommodate the new components, which might have different storage and handling requirements.

  8. Aftermarket and Spare Parts: The aftermarket for spare parts will evolve to include more 48V components. Suppliers in this sector need to adapt to the changing demand and potentially phase out certain 12V-specific parts.

  9. Environmental and Regulatory Considerations: The shift to 48V systems aligns with broader industry trends towards electrification and reduced emissions. Suppliers must be mindful of environmental regulations and the push for sustainable practices in manufacturing and disposal.

  10. Global Market Dynamics: The transition might be influenced by global market trends, including varying adoption rates in different regions and the impact of international trade policies on component sourcing.

In summary, the transition from 12V to 48V systems in the automotive industry requires a comprehensive adaptation of the supply chain, encompassing manufacturing processes, component sourcing, skills development, quality control, and logistics. While it presents challenges, it also offers opportunities for innovation and growth in an evolving market.

Mixed conversion

With some likelihood that not all vehicle systems will be converted to 48V, I asked ChatGPT4 to evaluate the impact of a mixed conversion.

The implementation of a mixed 12V and 48V electrical system in vehicles, where some systems operate on 48V while others remain on 12V, presents a unique set of challenges and effects:

  1. Complex Dual System: The most immediate effect is the increased complexity of having two distinct electrical systems within the same vehicle. This requires careful design and integration to ensure that both systems operate effectively without interfering with each other.

  2. DC/DC Converters: Vehicles will need DC/DC converters to step down the voltage from 48V to 12V for components that have not been converted. This adds extra components to the electrical system, increasing weight, cost, and potential points of failure.

  3. Compatibility and Integration Challenges: Ensuring seamless compatibility between 12V and 48V components can be challenging. This might involve sophisticated control systems to manage the interaction between different voltage systems and ensure stable operation.

  4. Weight and Space Considerations: Although a 48V system allows for thinner wiring, the need to accommodate two systems could negate some of these weight and space benefits. The integration of additional components like converters also requires careful planning regarding space utilization.

  5. Cost Implications: A mixed system could potentially be more expensive than a single-voltage system due to the need for additional components and more complex control systems. The development costs might also be higher due to the increased engineering effort required.

  6. Maintenance and Serviceability: Servicing a vehicle with a mixed-voltage system may require more specialized knowledge and tools. This could affect both the cost and availability of maintenance services.

  7. Reliability and Safety: With added complexity comes the potential for increased points of failure. Ensuring reliability and safety in a mixed-voltage environment requires thorough testing and robust design practices.

  8. Efficiency and Performance: While a 48V system can offer improved efficiency and performance for certain functions, a mixed system might not fully capitalize on these benefits if key components still operate at 12V.

  9. Upgrade Path and Future Proofing: A mixed system could be seen as a transitional solution, offering a path towards gradual electrification. It allows for the incremental introduction of 48V components while maintaining compatibility with existing 12V technology.

  10. Supply Chain and Manufacturing Impact: The dual system approach can impact the supply chain and manufacturing processes, as it requires the production and stocking of a wider range of parts and potentially more complex assembly processes.

In summary, while a mixed 12V and 48V system allows for partial adoption of higher voltage benefits and a transitional path towards full electrification, it also introduces increased complexity, potential cost implications, and challenges in integration, maintenance, and safety.

System Type Relative Cost Reasons
12V Systems Lowest Established technology, lower complexity, less expensive components
48V Systems Higher Advanced components (48V battery, converters), more complex integration
Mixed 12V/48V Systems Potentially Highest Components for both voltages, complex design, gradual transition to higher voltage

Evaluation of these responses

Electrek, a EV web journal, identified a number of issues with a 12V to 48V conversion. I thought it would be interesting to see which of these were identified in my simple analysis.

Electrek’s issues ChatGPT4’s evaluation
If you cannot convert all of a vehicle’s systems to 48V architecture, the benefits of using such an architecture start to diminish pretty quickly in the form of introducing new complexities (i.e., a hybrid 48V / 12V vehicle architecture). As such, most automakers have clung to 12V because they know it and it works. Identified that 48V is likely to be more expensive than 12V, and that as a mixed system is likely to be the most expensive that making such a change before all systems are reaady for 48V operation is the most expensive.
If an automaker decides to move to a 48V architecture, whatever car it builds must use 48V-ready accessories. But, suppliers aren’t incentivized to build such accessories without sufficient demand. While carmakers like Ford certainly have the power and scale to commission 48V parts independently, the per-unit cost of those components is likely to be substantially higher than their 12V equivalents — especially if they’re being produced in comparatively low volumes. And, many carmakers would be forced to make such a transition slowly over their entire vehicle lineup (it’s worth noting that ICE vehicles can use and would benefit greatly from 48V systems, too). And so, most carmakers stick with 12V. It’s a chicken-and-egg kind of issue. Identified this issue and pointed out that the supply chain will be burdened with extra R&D and manufacturing costs.

I think it is interesting that ChatGPT4 was able to identify the same issues as the author, and that it did so in a way that was consistent with the Electrek article. In addition, I think ChatGPT provided a bit more context and illumination on the issues. This was all done without using any advanced AI techniques, just a simple text generation model.

While this is a simple example, I think this is a good example of how AI can be used to help engineers identify issues and opportunities in a design.