"If the Chinese engineers don't arrive on time, then our cell line production will get impacted," Log9's co-founder and director, Pankaj Sharma, told Reuters. "We don't know by how much, but it can practically destabilise the production."

Log9 depends on engineers from China to set up imported machinery and upgrade existing ones at its facility. A delay of about four months in the issue of visas would hamper the speed at which its factory reaches peak production levels, Sharma said.

Earlier this month, an Indian government official said some manufacturers who rely on Chinese expertise have sought faster approval for visa applications of their vendors from China.

The comments come as India tries to position itself as a major manufacturing hub for companies diversifying away from China, which is grappling with slowing economic growth.

Log9's Bengaluru factory, its only manufacturing unit currently, has an annual installed capacity of 250 MWh of battery production.

Its batteries power the electric fleet of logistics giants Maersk and Blue Dart Express, and electric vehicle makers such as Quantum Energy and Hala Mobility amid a push from the Indian government for cleaner technologies.

Log9 has sold over 1,000 battery units so far in 2023 after clocking sales of 4,000 units last year, according to Sharma, who declined to disclose the production figures.

Log9, which counts Amara Raja Batteries and Malaysia's Petronas as its backers, raised $40 million in January at a valuation of about $210 million. The company will begin the next funding round by the end of this year or early next year, Sharma said.

(Reporting by Rama Venkat in Bengaluru; Editing by Dhanya Skariachan and Eileen Soreng)

By Rama Venkat