The first phase of CALB's Wuhan base was signed on May 31 last year, with a planned capacity of 20 GWh, and the main plant was topped out in March.

In addition to building new production bases, expansion of existing bases is another option for Chinese power battery giants.

CALB, one of China's largest suppliers of batteries for electric vehicles (EVs), signed a contract on May 11 with the authorities of the Wuhan Economic Development Zone in central Hubei province to expand its production base in the city.

CALB plans to invest RMB 12 billion ($1.78 billion) to add a planned battery capacity of 30 GWh at the site, according to a press release from the power battery giant.

The first phase of CALB's Wuhan base, with a planned capacity of 20 GWh, was signed on May 31 last year, and the main plant was topped out in March this year, according to the company.

With the signing of the new project, the planned capacity of the base will be increased by 150 percent to 50 GWh.

Founded in 2007, CALB is headquartered in Changzhou, Jiangsu province and currently has seven manufacturing bases in Changzhou, Luoyang, Xiamen, Chengdu, Wuhan, Hefei and Heilongjiang. It has a planned capacity of 200 GWh by 2022.

At the end of November last year, CALB said its capacity would exceed 500 GWh by 2025, an upward revision from the 300 GWh announced in June. The company expects to have 1,000 GWh of capacity by 2030.

The pace of CALB's capacity expansion has picked up significantly in the past six months.

On January 25, CALB signed a contract with the government of Huadu district, Guangzhou city, Guangdong province, to build a local base with a planned annual capacity of 50 GWh to produce power batteries and energy storage systems.

On January 26, CALB signed a contract with the government of Jiangmen city, Guangdong province to build another battery production base with a planned annual capacity of 50 GWh in the city.

On February 7, CALB started construction of the third phase of its Xiamen project, with a planned capacity of 40 GWh. Once the first, second and third phases of the Xiamen project are completed, it will have an annual capacity of 60 GWh in the city.

On March 22, CALB signed a contract with Meishan city, Sichuan province to invest about RMB 10 billion in a new power battery and energy storage system production base in the city to meet the continued soaring demand.

CALB is one of China's largest power battery suppliers, and data released yesterday by the China Automotive Battery Innovation Alliance showed that it installed 0.9 GWh in April, ranking third with a 6.79 percent share.

Contemporary Amperex Technology Co Ltd (CATL, SHE: 300750) and BYD (OTCMKTS: BYDDY, HKG: 1211) ranked the top two with 38.28 percent and 32.18 percent shares, respectively.