800V Architecture and Ultra-Fast Charging: Revolutionizing Electric Vehicles

Electric vehicles (EVs) are rapidly advancing, and two key technologies leading the charge are 800-volt (V) architecture and ultra-fast charging. These innovations offer significant benefits in terms of charging speed, efficiency, and overall vehicle performance. This article dives into the engineering mechanics behind these systems and provides a deeper understanding of their impact on the future of EVs.

What is 800V Architecture?

Most conventional EVs currently operate on 400V systems. While this has been sufficient for early models, the shift towards 800V architecture offers considerable performance improvements. Doubling the system voltage to 800V reduces electrical losses, allows for faster charging, and optimizes the overall design of the vehicle's electrical system.

The basic principle behind this is that higher voltage allows for reduced current for the same power output. Since power (P) is the product of voltage (V) and current (I), we can express this as:

P = V × I

For a given power output, increasing the voltage means the current can be reduced, which in turn reduces resistance losses (heat) as per Ohm’s Law (V = I × R). These resistance losses (P_loss) are proportional to the square of the current:

P_loss = I2 × R

By reducing the current, the system reduces these losses significantly. In practice, 800V systems have been shown to reduce overall power losses by up to 30% compared to 400V systems.

Faster Charging with 800V

One of the most immediate benefits of 800V architecture is faster charging times. While 400V systems typically charge at rates up to 150 kW, 800V systems can handle power levels as high as 350 kW. This allows an EV to add up to 200 miles of range in as little as 15 minutes. The relationship between power (P), voltage (V), and current (I) remains crucial here:

P = V × I

In the case of ultra-fast charging, doubling the voltage allows the system to deliver more power to the battery without requiring an increase in current. This reduces stress on components and allows for higher charging speeds with improved safety.

Automotive SiC ushers in a boom, and suppliers expedite their layout.

On the 800V high voltage platform, the withstand voltage of system components also needs to be leveled up to 800V, so do the corresponding components and materials. And under the high voltage architecture, battery pack, electric drive, PTC, air conditioner, on-board charger, etc. all require being re-selected as well.

As for the vehicle, high voltage technologies such as electric drive, fast charging battery, PTC, and DCDC have been production-ready. In fast charging battery’s case, in April 2021, Honeycomb Energy Technology under Great Wall Motor launched an all-new fast charging battery and corresponding battery cells.? The 1st-Gen 2.2C fast-charging battery features cell capacity of 158Ah and energy density of 250Wh/kg, and enables 20%-80% SOC in 16 minutes. It is to be mass-produced in the fourth quarter of 2021. The 2nd-Gen 4C fast-charging battery boasts typical charging capacity of 165Ah and energy density of >260Wh/kg, and enables 20%-80% SOC in 10 minutes. Its mass production is arranged in Q2 2023.

SiC features good voltage withstand, high stability, better frequency than silicon-based IGBTs, and small size, in the process of upgrading 800V high voltage platform components. It has drawn widespread attention in the industry.

In new energy vehicles, SiC is largely used in vehicle power supplies and motor controllers. Though still priced high in a relative sense and the inevitable higher cost by massive adoption in a single vehicle, the use of SiC devices can deliver a longer mileage range and slash the battery cost. The cost of a single vehicle is actually lower after offsetting the cost rise caused by SiC devices.

In the long run, the price of SiC devices will edge down. In China, silicon-based IGBTs are monopolized by foreign vendors, while in the SiC field Chinese suppliers like Huawei, Shinry Technologies and Zhuhai Enpower Electric have made successful deployments. Chinese players may outrun and replace their foreign peers in the race. The cost of SiC devices will drop further if localized.

The mass production of 800V high voltage platforms breathes new life into the development of SiC. Influential suppliers compete to expand SiC production capacity to satisfy the growing demand.

The 800V High Voltage Platform Research Report, 2022 highlights the following:

Introduction to 800V high voltage platform and its advantages, vehicle high voltage platform standards, charging pile high voltage platform standards, high voltage platform market size and competitive landscape, etc.;

800V high voltage platform’s impacts on the upstream industry chain (battery, electric drive, thermal management, etc.), electrical architecture design of the 800V high voltage platform, status quo of the downstream new energy vehicle sector, etc.;

Development stages of 800V high voltage platform, its availability on vehicles, and its use in charging piles, etc.;

Merits of SiC applied in 800V high voltage platform, its application at the vehicle end, its application in charging piles, status quo of SiC industry, etc.;

Deployments of OEMs and suppliers in 800V high voltage technology.

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Efficiency Gains and Weight Reduction

Beyond faster charging, 800V systems also contribute to overall vehicle efficiency. By reducing the current, the wiring can be made thinner, which reduces the vehicle’s weight. It is estimated that transitioning from 400V to 800V systems can reduce the weight of the wiring by up to 40-50%. Lighter vehicles experience lower energy consumption, leading to longer ranges.

For example, if a vehicle sheds 100 kg of weight, this can result in a range increase of approximately 10-12%, depending on the vehicle’s aerodynamics and driving conditions. The efficiency gains from reduced wiring weight are significant, as less energy is needed to move the vehicle, and more of the stored battery energy can be used for propulsion.

Thermal Management and Component Durability

Higher voltage also improves thermal management. In 400V systems, higher currents lead to greater heat generation, which can stress components like the inverter and wiring. In 800V systems, since the current is lower, less heat is produced, which allows components to operate at cooler temperatures and with less thermal degradation over time.

The Future of Charging Infrastructure

Charging infrastructure is adapting to meet the needs of 800V EVs. Ultra-fast charging stations capable of delivering 350 kW are being deployed by networks such as Ionity and Electrify America. These stations enable 800V vehicles to charge rapidly, reducing downtime and making long-distance travel more convenient.

Conclusion

The shift to 800V architecture and the deployment of ultra-fast charging systems represent a significant leap forward in the evolution of electric vehicles. With faster charging times, improved efficiency, and better thermal management, these technologies are paving the way for more practical, high-performance EVs.