SHANGHAI (Reuters) - China's BYD has unveiled a megawatt charging system that it says can charge an EV as quickly as filling up a fuel tank, and said it will build a network across China, igniting a new super charging race.

Here are more details about the Chinese electric vehicle giant's new technology and why the fast-charging space is attracting interest:

WHY DOES FAST-CHARGING EV TECHNOLOGY MATTER?

Drivers sceptical of EVs have cited worries that their batteries could go flat during long-distance drives, prompting automakers to come up with fast-charging as well as battery-swapping technology as solutions.

Chinese automakers are increasing using such technologies as key selling points to attract buyers in a hyper competitive market and such technologies have been credited for contributing to the high adoption of EVs in China. Tesla also offers ultra-fast chargers.

HOW DOES BYD'S NEW SYSTEM COMPARE TO OTHERS?

BYD said its so-called "super e-platform" will be capable of peak charging of 1,000 kilowatts (kW), enabling cars that use it to travel 400 km (249 miles) on a 5-minute charge.

To achieve such performance, BYD said it had developed a package of technologies including batteries with a 10C charging multiplier, which means they can be charged at 10 times the battery's capacity per hour. Others include high-power motors, high-volt silicon carbide power chips and fast chargers that support 1,000 kW of power.

By comparison, Tesla mainly sticks with a 400-volt system that can charge at up to 250kW for its EVs. The exceptions for the U.S. automaker are its Cybertruck that runs on a 800-volt architecture with a maximum rate of 350kW, and Semi truck that has a 1,000-volt powertrain.

Zeekr, Geely's premium EV brand, launched last year an 800-volt platform that can charge 80% of a 75-kwh battery in its Zeekr 007 sedan from 10% in 10.5 minutes. Li Auto and Xpeng have similar technology that can achieve more than 400 km driving range on a 10-minute charge.

WHY DOES BYD NOW WANT TO BUILD A CHARGING NETWORK?

BYD accounts for more than a third of the EV sales in China but its owners have largely relied on other automakers' charging facilities or public charging poles run by third-party operators to date.

The company said the latest super e-platform required its own fast chargers and that it would build more than 4,000 such charging stations across China, without specifiying a time frame. Founder Wang Chuanfu, at the unveiling event on Monday,

also appealed to external investors, saying the company would welcome their help in building more.

BYD would, however, be playing catch up: Chinese automaker Nio has the most extensive charging network in China including nearly 2,700 fast charging stations.

Tesla had led with its efforts since 2014 in China and built more than 2,000 stations, or 11,500 Superchargers as of September.

Smaller players such as Li Auto, Xpeng and Zeekr have also been ramping up efforts to expand their fast-charging networks. Li Auto said last week that it had built 1,900 fast charging stations since April 2023.

Zeekr said last year that it aimed to build 100,000 ultra-fast charging poles, or 2,000 ultra-fast charging stations nationwide by 2026.

Huawei has also built liquid-cooled ultra-fast charging piles that supports a maximum charging power of 600kW and vehicles of up to 1,000-volt architecture. Its deployment of charging facilities including the ultra-fast chargers had exceeded 50,000 piles as of last year.

ARE THERE ANY CONCERNS?

Analysts, however, have warned that mass adoption of fast-charging technology will put extra pressure on power grid capacity, which would require additional efforts and investments to upgrade the infrastructure.

BYD said it would tackle the challenge by equipping an energy storage unit with each of its fast chargers, which analysts said would make such facilities more costly.