Bon Voyage – How to Keep EVs “Alive” Across Oceans En Route to Global Expansion
In recent years, the electric vehicle (EV) industry has experienced a remarkable shift toward global expansion. Fast-growing manufacturers in China are investing in massive carriers, transporting thousands of new cars at a time from production hubs to markets worldwide. In this blog, we explore the rising scale of transoceanic car shipping and the innovative technologies making it possible.
Cars making ocean voyages have long been a crucial part of automakers’ international operations. For decades, companies like Toyota and Nisson have relied on partnerships with major shipping firms operating fleets of specialized car carriers. The rise of EV giants, however, is taking this to another level. BYD, already the world's largest EV maker, has recently launched its own fleet of container ships to meet soaring international demand.
Less than a year after launching BYD Explorer No.1—with a capacity of 5,000 electric cars—the company recently unveiled its fourth and the world’s largest vehicle carrier. The BYD Shenzhen is 219 meters long and 37.7 meters wide, capable of transporting 9,200 cars across the ocean. These vessels regularly carry EVs from ports in northern and southern China to destinations across Europe, underscoring the critical role of maritime logistics in the global EV market.
By operating their own fleets, EV manufacturers can reduce dependency on third-party shipping companies, potentially lowering transportation costs and improving profit margins. This is especially important given the recent surge in car-carrier rental prices.
Owning container ships also gives EV makers greater control over their supply chains, ensuring timely deliveries and reducing the risk of delays caused by shipping bottlenecks. This control is vital for maintaining brand reliability and reputation in international markets.
The Role of Roll-On/Roll-Off Carriers
One of the most popular approaches for transporting vehicles across oceans is the use of roll-on/roll-off (RoRo) carriers. These specialized ships allow cars to be driven on and off the vessel, making loading and unloading quick and efficient. However, this method requires vehicles to remain functional throughout the journey, which can span several months. This long voyage poses a unique challenge for EVs.
The Battery Challenge
In this previous blog, I explained why most fully electric cars still rely on traditional lead-acid batteries to supply 12 V power to all electric subsystems. Drivers of both ICE and electric cars can attest that these old-school batteries would drain in just a few weeks. Even when replaced with lithium-ion batteries, periodic charging is still required from the main high-voltage traction battery, which can also deplete after idling for months onboard a ship.
Another option is to draw power from the high-voltage battery pack via the vehicle’s main high-voltage to low-voltage DC-DC converter. The issue is that these converters are optimized for full-load efficiency, not low-load operation. When supplying standby power to 12 V systems, their inefficiency leads to significant energy loss. As a result, even a fully charged battery pack may not last the entire ocean voyage.
Recharging a completely drained EV battery is much more complicated than jumpstarting a car. It requires access to a charging station for an extended period of time. Onboard a carrier, where space is limited and resources are constrained, recharging thousands of batteries simultaneously presents a logistical nightmare.
The Solution: Power Integrations' InnoSwitch3-AQ Flyback Switcher ICs
In the same previous blog I mentioned above, I introduced a micro-DC-DC converter design featuring Power Integrations’ innovative InnoSwitch3-AQ flyback switcher ICs. This rugged power supply can safely draw from the car’s high-voltage battery pack, supporting systems needed to eliminate the need for a 12 V battery.
The ICs achieve greater than 90% efficiency across the load range while consuming less than 15 mW at no-load, which means all 12 V systems in the EV can remain in standby mode—no matter how long they need to stay at the port, on the ship, or in a vehicle preparation center.
New 1700 V SiC-based members of the InnoSwitch3-AQ family are designed to support 800 V BEV systems, providing sufficient creepage such that reinforced isolation can be achieved without the need for conformal coating. A new reference design using this state-of-the-art device also employs a planar transformer, further enhancing the space-saving benefits of this 12 V battery-replacement solution.
The adoption of advanced power solutions—such as AEC-Q100-qualified InnoSwitch3-AQ switcher ICs—highlights the importance of technological innovation in addressing the wide-ranging challenges facing the EV industry. These innovations not only improve the efficiency and reliability of the vehicles themselves but also the transportation systems critical to the industry’s global growth.
