What Are The Differences Between 400- And 800-Volt EVs?
Technology moves fast in the automotive space, and particularly fast in the world of electric vehicles. It wasn't all that long ago that the original Nissan Leaf took the world by storm, with an EPA-rated 73 miles of range, 107 horsepower, and 207 pound-feet of torque. These numbers were enough to see the Leaf secure solid success on showroom floors, but in 2025, we expect way more from our EVs.
The most advanced production models now boast over 1,000 horsepower, and ranges that exceed 400 miles from a single charge. One of the more prominent reasons why EVs are getting ever more effective, and ever more efficient, is the shift that's happening from 400- to 800-volt architectures. That number — be it 400 or 800 — refers to the nominal voltage of any given EV. The car's voltage does fluctuate depending on factors such as the state of charge, and the temperature. For example, a 400-volt EV may run anywhere between 300 and 450 volts.
While most EVs are still being built using 400-volt systems, many automakers are looking to shift to 800-volt systems soon, while some are already there. Doing so will bring numerous benefits in efficiency and performance, although one considerable downside to 800-volt systems is stopping other carmakers from making the switch.
800-volt systems are far more efficient, but it comes at a cost
One of an 800-volt system's greatest benefits is that it requires half the amperage of a 400-volt system to return the same charging speed, as multiplying voltage by amperage provides the charging speed. Higher charging rates incur more losses, so by lowering the current and raising the voltage, the whole process becomes more energy efficient.
Another win for the 800-volt system is that, due to the lower amperage current within the EV, thinner cables can be used. Thinner cables means less resistance and less heat, which is more efficient and makes heat management easier. And thinner cables are lighter, which reduces the EV's overall weight, further improving efficiency and performance. Less heat running through the battery also helps battery health and longevity, although 800-volt EVs haven't been in production long enough for us to have a truly accurate picture of their battery degradation.
If this all seems like a win-win-win in favor of the 800-volt systems, that's because it largely is. However, there is one great downside to the 800-volt designs, and that's cost. The 400-volt tech is older, established, and proven reliable. The cost of components is significantly less, and this all translates to a more affordable finished product. The 800-volt EVs are all well and good, but if they're out of reach for the average motorist — especially now that U.S. tax incentives have been canceled — their effectiveness has to be questioned.
800-volt EVs are on their way
We do already have some EVs on the road that use 800-volt systems. For example, Rimac pioneered the technology when it launched its quad-motor hypercar, the Nevera, which boasted a mind-boggling 1,914 horsepower. In more attainable circles, the Kia EV6 and Hyundai Ioniq 5 use similar 800-volt frameworks, as do the Porsche Taycan and Audi e-Tron GT.
This is only the start, though. BMW has already expressed its wishes to use 800-volt architecture with its Neue Klasse model range, and Mercedes is looking to do the same with its larger EQ models and up-and-coming new CLA. Volvo looks to be moving in the same direction with its updated EX90, which suggests that in the coming years, such frameworks might start to be the norm rather than the exception.
This would translate into more efficient EVs with faster charging times, and perhaps more efficient charging stations, too, as at the moment these are typically geared around 400-volt systems. On the downside, it might mean that — at least at first — EVs begin to spike in price. The cost of manufacturing may decrease once the tech becomes mainstream, but until then, it looks as if consumers will need to reach deeper into their pockets in order to get behind the wheel of next-gen 800-volt EVs, or automakers will have to slash their profits.
