Chinese EV giant BYD has stirred the electric mobility world with the unveiling of its new ‘flash charging’ technology, delivering up to 1.5 megawatts of power and allowing charging from roughly 10% to 70% in about five minutes, or charging times that approach those of refueling a gasoline car.

The announcement has sparked a wave of speculation about whether ultra-fast charging could undermine battery swapping, a model championed primarily by Chinese EV maker NIO. If charging becomes nearly as fast as swapping a battery, does the latter still make sense?

Reality is more nuanced

Megawatt charging is technically plausible and increasingly within reach. BYD’s system reportedly allows charging from 10% to 97% in under ten minutes in optimal conditions, with the company planning to deploy a large network of ultra-fast chargers in China.

Reports suggest BYD aims to build up to 20,000 stations domestically, with overseas expansion in Europe and the US starting around 2026.

Such power levels are significantly higher than those of most public charging infrastructure today. Typical DC fast chargers in Europe deliver between 150 and 350 kW, while even the fastest current systems rarely exceed 500 kW. A charger capable of delivering 1.5 MW, therefore, represents a step change in charging performance.

Significant engineering challenges

One of the biggest hurdles is heat. Charging a large battery in just a few minutes can generate substantial thermal loads within the cells.

To avoid degradation or safety risks, batteries require sophisticated cooling systems and cell designs optimized for extremely high charge rates. Even then, peak power is usually available only for a short portion of the charging curve.

Another constraint lies in the charging hardware itself. Delivering megawatt-scale power requires liquid-cooled cables and high-voltage architectures typically in the 800- to 1000-volt range or higher.

Cars must also be specifically engineered to handle such extreme charging rates, with reinforced battery packs, advanced cooling, and high-power electronics.

This means only vehicles built on dedicated next-generation platforms, such as BYD’s new Super e-Platform, will initially support megawatt charging, and the additional hardware is expected to add several hundred to possibly a few thousand euros to the cost of a vehicle.

The connectors and infrastructure resemble those of the Megawatt Charging System currently being developed for electric trucks rather than those of conventional passenger car chargers.

More than a hundred homes

Perhaps the most overlooked challenge is the electrical grid. A single 1.5-MW charger can draw as much power as more than a hundred homes. A station with several such chargers operating simultaneously could require industrial-scale grid connections.

To address this, many ultra-fast charging designs, including the ones BYD is expected to deploy, rely on large stationary batteries integrated into the charging station.

These batteries act as energy buffers. Instead of drawing megawatt-level power directly from the grid, the station slowly charges its own battery at a lower rate. When a car plugs in, the station battery discharges rapidly, combining with grid power to deliver the high charging peak.

This approach allows stations to deliver extremely high-power bursts without requiring equally large grid connections, though it adds cost and complexity to the infrastructure.

So where does that leave battery swapping?

In practice, megawatt charging and swapping address similar problems — minimizing downtime for EV users — but they do so in different ways.

Ultra-fast charging reduces waiting times dramatically, potentially approaching the convenience of refueling a combustion vehicle. Battery swapping, on the other hand, replaces the depleted battery with a fully charged one in a matter of minutes.

Swapping also offers advantages that charging does not entirely eliminate. It ensures a fully charged battery every time, avoids repeated ultra-fast charging that could accelerate battery wear, and can be particularly attractive for commercial fleets that must minimize downtime.

Beyond technology, another key comparison between ultra-fast charging and battery swapping is throughput — how many cars each system can serve.

Battery swapping has a clear advantage here. A modern NIO Power Swap Station can complete a swap in about 144 seconds and handle up to roughly 480 vehicles per day per station under optimal conditions.

In China, NIO’s nationwide network has demonstrated its scalability, performing more than 150,000 battery swaps per day across its stations during peak travel periods.

Megawatt charging narrows this gap but does not eliminate it. A five-minute charging session theoretically allows around twelve vehicles per hour per charger, or roughly 250 vehicles per day if operated continuously.

In practice, throughput will be lower due to queuing, payment time, and the fact that ultra-fast charging speeds are typically maintained only for part of the session.

More vehicles per day

In other words, while megawatt charging dramatically reduces waiting times compared with today’s fast chargers, a single swapping station can still process more vehicles per day than a single charging point.

That said, swapping infrastructure requires a different kind of investment. Stations must store dozens of battery packs, maintain complex robotics, and rely on standardized battery formats across multiple vehicle models.

Ultra-fast charging, by contrast, works with conventional vehicle architectures and can serve many brands as long as charging standards are compatible.

Megawatt charging could therefore reduce the practical advantage of battery swapping for private drivers, especially if charging times approach the five-minute mark. For many motorists, plugging in for a few minutes may feel almost as convenient as replacing a battery.

Yet swapping retains advantages in specific use cases. Fleet operators, taxis, and logistics vehicles may still benefit from guaranteed fully charged batteries and extremely predictable turnaround times. In dense urban markets where home charging is limited, centralized battery management can remain attractive as well.