What is 800V charging? A complete guide

• 800V charging will replace 400-volt charging in EVs (eventually)
• In tests, 800V can charge twice as fast as 400V
• The higher voltage creates a lower current, reducing heat
• Currently, 800V is expensive to engineer, so only a few cars have it
• In the near future, we predict all electric cars will have 800V charging

How does charging from 5-80% in less than 20 minutes sound? That’s what 800V architecture offers.

With an electric vehicle, either the voltage or current can be increased to boost power flowing to the battery. When the current increases, cables need to be thicker because more space is needed for electrons to move through.

A better solution to increasing power flowing to the battery is increasing the voltage, which lowers the current, reducing cable thickness due to less resistance in the conductors as electricity flows through the cables.

Why is 800 volts faster?

800 volts is faster because it lowers the current; the lower the current, the lower the resistance (energy) loss in the conductors. 800 volts is simply more efficient than 400 volts, experiencing less energy loss for the same amount of power consumed.

800V is double the voltage of 400V. With double the voltage, an electric car can charge at much faster speeds, typically up to 360kW.

What 800V means for your charging cable

One question that comes up often is whether 800V architecture changes the cable you need for home charging. The short answer is no. Your Type 2 to Type 2 cable is used for AC charging, which operates at a completely different level to the DC rapid charging where 800V makes its difference.

When you plug your Hyundai Ioniq 5 charging cable into a home wallbox with a Type 2 cable, you are charging at 7.2kW on a single phase supply regardless of whether the car has 400V or 800V architecture. The voltage advantage only kicks in at DC rapid chargers, which have their own tethered cables and handle everything internally.

So while 800V is transforming the rapid charging experience, your daily home routine stays the same. A 32A Type 2 to Type 2 cable rated at 7.2kW is all you need for overnight charging. The Ioniq 5 will pull the same 7.2kW whether it has the most advanced battery architecture on the market or not.

Where 800V does benefit you at home is efficiency. Less energy is lost as heat during charging, meaning marginally more of what you pay for ends up in the battery. Over a year of daily charging, that adds up.

Why does 800 volts unlock more range?

800 volts unlocks more driving range because vehicles are lighter; cables are thinner, wiring looms are smaller, and the battery is configured to utilise power more efficiently, with the cells inside the battery losing less power during consumption.

Why is 800V better than 400V?

Today’s electric vehicles have either a 400V or 800V architecture. 400V is more common because the technology is more established, but more electric vehicles are launching with 800V, like the Kia EV6 and Porsche Taycan.

The question is, why is 800V better?

800V is better than 400V because it enables faster charging speeds without adding heat and requiring new cables and electronic components.

By doubling the voltage flowing to the battery, we enable twice the charging speeds while halving the current, and it is the current that adds heat.

It means 800V cars can charge twice as fast as 400V cars with the same cables, and the cabling and electrical components in the vehicle can be thinner and smaller. These benefits mean 800V is the natural successor to 400V architecture. 

Cars with 800V can also weigh less than cars with 400V, further improving range and performance.

Why is 800 volts a big deal?

800 volts is a big deal for two simple reasons:

• 800 volts = faster charge speeds
• 800 volts = lighter, more efficient vehicles

800-volt charging architecture slashes charging times without thicker cables, reducing weight and range. For example, in just over five minutes, the Porsche Taycan gets a 62-mile range boost and the charge time for 5% to 80% is just 22.5 minutes.

Today, most electric cars have a 400-volt architecture, which describes the maximum voltage that can flow between the cells inside the battery.

800-volt architecture is an upgrade over 400-volt architecture, unlocking significantly faster EV charge speeds by increasing the voltage and reducing overheating.

Several electric cars have adopted 800 volts architecture, which is the natural successor to 400 volts architecture until new battery technology is available.

Understanding volts and current

The reason 800 volts gives us faster charging is that the battery receives more power from the charger. In a 400 volt system, there is double the amount of energy loss because the current is high. The current creates resistance losses in the conductor (energy loss) so it is inefficient, especially at rapid charging speeds.

Think of it this way: a higher voltage pushes through more power not by increasing the power draw, but by reducing resistance in the wire. Resistance has an energy penalty, so it makes absolute sense to use 800 volts in electric cars.

How 800 volts unlocks faster charging

The heat generated by DC fast chargers overheats batteries with 400V architecture, which is why charge speeds drop off a cliff after 80%.

800 volts solves this problem by changing the way the cells are connected inside the battery, allowing a lower current but a higher voltage to be used. In an 800V battery, the cells are connected in series.

This tweak improves thermal efficiency, stopping the battery from overheating at higher charge speeds. Another benefit to 800V architecture is charging cables can be the same size or even thinner, since only the voltage increases, not the current.

While 800V isn’t a brand-new charging technology, it is one of the biggest upgrades electric cars will experience over the next upgrade cycle.

The only downside to 800V charging is it is more expensive to design and engineer, so the technology has a barrier to entry for cheap electric cars.

The Porsche Taycan and Hyundai IONIQ 5 have 800V technology, and Tesla may introduce it in future models.

Can we go faster than 800 volts?

It isn’t out of the question that electric cars in the future will have 1000 volt architecture, which would unlock even faster charge speeds. However, let’s not jump the gun – 800 volts is still in its infancy.

If 800 volts is so great, why isn’t is everywhere?

Make no mistake, 800 volts is great and a huge upgrade over 400 volts. However, it requires completely new engineering and design. The architecture is unique to each manufacturer; they don’t share blueprints. The technology (or how they apply it) is a closely guarded secret.

For example, Porsche and Hyundai’s 800-volt technology is different – different thermal management, different loop configurations, different battery densities, different design principles… you get the idea.

At the moment, 800 volts is a state-of-the-art charging technology, reserved for high-end vehicles. Hyundai bucked this trend with the mid-priced IONIQ 5, but they are a special case with massive engineering budgets.

Tesla and 800 volts

Tesla hasn’t announced any plans for 800-volt charging, but they tend to go where the puck is going. 800-volt charging is the future, so Tesla will get on board eventually.

We wouldn’t be surprised if Tesla announced 800-volt charging alongside a new type of battery, possibly with the next-generation Model S or Cybertruck.

Are there any downsides to 800V charging?

The biggest downside is the architecture requires new engineering. Cars with 400V today cannot be converted to 800V by replacing a few parts, so 800V charging is very much a technology for next-generation vehicles.

There are also a few design and engineering limitations, including more insulation required for the HV conductors, and lower power density in the motors, caused by thinner wires and greater insulation thickness.

It should be said these downsides are mute for vehicle owners. The only downside for owners is the fact that most chargers don’t support 300kW+ charge speeds, rendering the 800V technology pointless a lot of the time.

This will change in the future though as more ultra-rapid chargers with speeds greater than 300kW are rolled out.