Video: How EV Architecture Affects Efficiency and Charging Speeds

While range is usually the main selling point of an EV, it's important to understand how and why an electric vehicle charges quickly and is efficient. In both cases, those can increased with a change from a 400-volt to an 800-volt architecture. It's why many automakers are moving their mid to luxury-level EVs to an 800-volt architecture. But don't expect 400-volt EVs to go away anytime soon. 

800-Volt Architecture

It's easy to see why an automaker and its customers would want an 800-volt architecture EV. Even at first glance, the benefit of having a vehicle that charges quicker and is more efficient with less wiring seems like a home run. The architecture allows for increased energy delivery without increasing amperes/current. The results in higher charge rates without increased waste due to heat. 

The increase in voltage also means less wiring in an EV which reduces weight. When the majority of potential buyers on the market are looking at vehicle range, reducing weight in a vehicle is one of the key items needed to achieve this. 

Overall, an 800-volt architecture is more efficient than that of a 400-volt system. 

The downside is that the 800-volt architecture supply infrastructure isn't as robust as that of the 400-volt architecture. The result is a more expensive vehicle compared to that of a 400-volt counterpart. 

400-Volt Architecture

The main benefits of this architecture are price and interoperability with much of the current charging network. The 400-volt supply chain has been in use for decades with many hybrids and plug-in hybrids based on a 400-volt architecture. It's no wonder that many automakers opted for 400-volt architectures in their previous and current EVs. 

WIth that in mind, it's also not surprising that much of the charging infrastructure is using 400-volt stations. 800-volt vehicles have to add additional hardware to work with these stations while 400-volt vehicles do now. 

The drawback is that 400-volt vehicles can't charge as quickly as 800-volt vehicles. To reach the speeds of 800-volt vehicles, 400-volt EVs require more current which creates more heat. That heat is waste and begins to eliminate efficiencies in the system. 

Still, 400-volt is less expensive and many automakers will likely continue to use the architecture on inexpensive EVs even after moving their mid-to higher-tier vehicles to 800-volt systems.