BYD’s Ambitious Charging Claim
Build Your Dreams (BYD), a leading Chinese automaker, is making waves in the EV industry. Recently, the company unveiled a 1,000 kW fast-charging solution, boldly claiming the ability to add 248 miles of range in a mere five minutes. This would put BYD significantly ahead of the current competition.
The fastest-charging EV in the United States—the Lucid Air Grand Touring—can add an estimated 200 miles of range in 12 minutes. Tesla’s 3rd-generation superchargers currently supply a maximum of roughly 250 kW, which equates to approximately 175 to 200 miles of range in 15 minutes. Tesla has plans to increase this to 325 kW and beyond.
BYD’s claim is certainly an exciting prospect. Let’s examine the system and the potential long-term impacts of fast-charging an electric vehicle’s battery pack.
BYD’s Tech by the Numbers
BYD’s Super-e platform is said to utilize a 1,000-volt architecture, which is considerably more voltage than most EVs on the road today can handle. The Lucid Air operates on a 900-volt architecture, while most other EVs use systems of 800 volts and below.
It’s important to note that electric vehicles are limited not only by the charger’s power supply but also by the electricity they can accept. Charging speed depends on several factors, including battery chemistry, battery temperature, and the battery’s state of charge.
BYD attributes these impressive numbers to a special battery technology utilizing a 1,500 V silicon-carbide “power module.” We looked at their website to learn more about this technology but found few details. The Chinese automaker also claims the 580 kW electric motor(s) that complement the new platform will be able to reach 30,511 rpm, with a power-to-weight ratio of 16 kW/kg. The brand claims the new propulsion system can accelerate its vehicles to 62 mph in about two seconds — which would make them some of the fastest-accelerating EVs in the world.
Preconditioning
Preconditioning is a key step in optimizing EV charging performance. It heats or cools the battery to the optimal temperature before charging begins, which promotes fast charging times, increases efficiency, and can also improve battery longevity.
Batteries don’t literally contain electricity, but they contain chemicals that react to create electricity through chemical reactions. These reactions slow down in extreme temperatures, which is why most EVs have built-in heating and cooling systems to maintain the right temperature window.
The Wear and Tear of Fast Charging
Charging speed remains a major hurdle for convincing owners of internal combustion vehicles to switch to EVs. However, ultra-fast charging can be detrimental to battery health and longevity.
Rapid charging can generate a lot of heat, accelerating the chemical reactions within the battery. This means the battery degrades faster and has to work harder. Many manufacturers recommend against fast charging, especially near the vehicle’s maximum state of charge. This could also increase the chances of dendrites, which increase the chance of a short circuit.
Charging Curves and the 20-80% Rule
BYD’s claimed 1,000 kW figure is impressive, but it can also be misleading. Chargers can’t operate at full power all the time because the battery would overheat quickly. Charging power varies over time, sometimes displayed via “charging curves.” Several factors can throttle the speed: battery capacity, state of charge, temperature, and charger type. Initial charging power can be high, but as the battery fills up, the power plateaus and decreases.
Many EV enthusiasts follow the “20-80% Rule,” keeping the battery’s state of charge between 20 and 80 percent to maximize battery health and longevity.
What’s the Best Way to Charge?
EV ownership is a personal experience. If you have a home charger, trickle charging overnight is a great way to slowly add range. Apartment dwellers and those without a garage may have few options besides fast chargers.
Thankfully, charging stations are multiplying. Seeing them in office parks, parking garages, and parking lots is a realistic alternative to creating a battery that can charge “as fast as a fill-up.” A 2022 J.D. Power study estimated that the average American motorist drives about 37 miles a day. This kind of rapid-charging solution appears to be designed to make road trips easier, not to revolutionize daily life for EV owners.
