Paris, BYD promises with the Denza Z9GT a 5-minute recharge to compete with a full tank of gasoline. Behind this slogan, a much more complex electric mechanics.
An electric car that recharges almost as fast as a full tank of gasoline: on paper, this still sounds like a showroom promise. Yet this is exactly what BYD is highlighting with its high-end Denza brand and its large sedan-break Z9GT, unveiled in Paris with great fanfare. Amidst the gilding of the Opéra Garnier, Stella Li, executive vice president of the Chinese giant, declared: “This car will redefine your relationship with driving.” A statement sure to pique the curiosity of all those who find the fast charging stations still too slow.
Behind the scenes, BYD is making a very simple promise to the driver: stop for a few minutes, leave with a battery almost full, even in the dead of winter, and an autonomy of about 600 km. To achieve this, the manufacturer has developed a new technology called Flash Charging, which combines a specific battery, in-house electronics, and ultra-powerful terminals. The key now is to understand how this combination actually achieves what others don’t yet offer.
For BYD, the challenge is clear: to reassure all those who fear spending too much time plugged into a charging station. This tackles the main issue that many critics cite against adopting electric vehicles: long charging times. Diego Pareschi, director of electric vehicle charging for Europe at BYD, based in Amsterdam, as quoted by Automotive News Europe, explains that the Denza Z9GT carries a 122 kWh battery, which can go from 10% to 70% in five minutes, then reach 97% in nine minutes. BYD even claims that these times “compete with the conventional refueling time at a petrol station.”
This fast charging translates on the road to an advertised autonomy of about 600 km on the WLTP cycle, just a bit more than a Porsche Taycan with an announced range of 590 km. The difference lies mainly in the charging station: a Taycan goes from 10% to 80% in 18 minutes, according to Porsche, while BYD promises a 10-70% in 5 minutes for the Z9GT. Moreover, the Chinese brand particularly emphasizes the winter conditions. Even in very cold weather, down to -30 °C, BYD assures that these times would only be extended by about three minutes. “Charging in cold weather can be extremely painful,” explains Pareschi. “If the battery is not heated, sometimes it takes two or three hours for a full charge, which hinders the adoption of electric vehicles.” The goal here is to keep the stop very short, even when the temperature drops.
A technology integrated for ultra-fast charging
To achieve this ultra-fast charging, BYD’s success all stems from the in-house integration of the group. BYD designs the battery, the electronic part of the vehicles, and the Flash Charging terminals, which allows it to optimize the whole process. The Z9GT is the first BYD sold outside of China to use the second-generation lithium-iron-phosphate Blade battery. Diego Pareschi explains that it benefits from “a new chemistry offering higher energy density and faster lithium-ion channels, reducing the heat generated during charging.” This LFP chemistry, less prone to overheating than other types of batteries, is an asset when delivering so much power in a short amount of time. The entire system relies on an 800-volt electrical system in the car, designed to handle much higher powers than a traditional vehicle.
Powerful stations but a more subtle operation than it seems
On the infrastructure side, BYD is not talking about a simple charging station a bit stronger than the others. This is a charger with a maximum power of 1,500 kilowatts, about 2.5 times more than the fastest current stations in service in Europe. For the driver, this translates to a charging rate of up to 10 C, with a striking promise: “a second of charging would allow you to recover 2 km of autonomy.” However, this power does not come directly from the electrical network. “It is not necessary to provide 1,500 kW of power at the charging point from the grid, as much of the energy will be stored to charge the batteries – hence the term ‘Flash Charging’,” details Pareschi.
BYD states that a 200 kW power supply at the station is sufficient: the terminal acts as an energy reservoir that is filled gradually before quickly emptying into the car. These stations will first be installed in Denza dealerships, then deployed with third-party operators, and they will be compatible with all electric vehicles. BYD even considers connecting its plug-in hybrids to them and hints that models from other brands could pay more or be limited if they do not support these power levels. The real test lies in how often drivers will truly benefit from these advertised 5 minutes to fill their battery.
