Accelerating EV charging: 400km of range in 5 minutes

How are Chinese electric vehicle (EV) makers able to promise that a five-minute charge can add up to 400km of driving range?

Range anxiety is a common concern that plagues both current and future EV drivers. There are two causes of this: the distance to the next charger and the time needed for charging.

Modern navigation systems – whether over smartphones or those built into the cars – are able to factor in the EV’s state of charge when planning their routes, alleviating the first concern. To address the second issue, manufacturers have been pushing for ever-faster charging speeds. This is measured in kilowatts (kW), the unit of power, and is defined as the rate at which electrical energy is transferred in a circuit.

Currently, charging power for EVs range between 200kW and 400kW. To achieve higher charging capacity, battery voltage architecture needs to be increased. Entry-level EVs typically use 400V batteries, while higher-end models are featuring 800V systems, influencing how quickly they can be charged.

Now, BYD is rolling out 1,000kW charging in China and Europe. It starts with its 1,000V battery pack.

Since electrical power is a product of voltage and current, a higher battery pack voltage equates to higher power. Additionally, and with reference to this equation, the battery manufacturer can maintain constant current. This keeps copper wires thin, thereby ensuring that both cost and weight remain low.

Another benefit of this is smaller power losses caused by heat. Overall, greater thermal efficiency is achieved in BYD’s 1,000V battery pack.

It takes equally capable chargers and EVs to be able to take advantage of the technology.

BYD chargers in China use energy storage systems to deliver this power. This lets the system pull electricity from as many resources as it requires while minimising the risk of overloading the power grid.

In real terms, this translates to a peak charging speed of 2km per second and an average of five minutes to gain 400km of operating range.

In the vehicle, certain design considerations are required for it to accept 1,000kW charging. Superior thermal management of the battery pack is required to keep the temperature of the battery at safe levels.

To deal with the incoming electricity, advanced vehicle electronics coupled with smart battery management systems allows each cell to be analysed and charged as quickly and efficiently as possible, while ensuring longevity.