CHINA's second-biggest carmaker, FAW Group, is teaming up with start-up Nio to promote battery-swap technology that would allay concerns among electric-vehicle (EV) owners about driving long distances, reports Hong Kong's South China Morning Post.

The two companies signed an agreement for strategic cooperation in pushing for battery technology standards, developing EVs with chargeability and swapability, and building a recharging service ecosystem, according to a statement in Shanghai.

FAW, which counts Volkswagen and Toyota as partners, became the largest carmaker to support Shanghai-based Nio's technology amid a surge in EV adoption. The technology will allow electric-car owners to quickly swap a spent battery for a fully-charged pack, giving drivers confidence to make long trips nationwide.

China is the world's largest EV market, where four out of every 10 new cars are powered by batteries.

"The strategic cooperation is expected to further push forward the standardisation of battery-swap technology, the extension of the business model of battery swap, and a larger scale of battery swapping network," said Nio.