(Yicai Global) Sept. 16 -- The biggest battery manufacturers in China made CNY16.5 billion (USD2.3 billion) in profit from January through July, an annual gain of 63.7 percent, according to data published today by the Ministry of Industry and Information Technology.

The firms, which included only those whose revenue topped CNY20 last year, earned a total CNY408.9 billion (USD57.8 billion) in revenue during the seven months, a 14.5 percent gain, the ministry said.

They made more than 8.3 billion lithium batteries, 10 percent more than the year-ago period, with the total voltage of lead acid batteries produced reaching 11.2 gigavolts, a 4 percent rise. The companies also manufactured 3.8 percent more primary cells and battery packs, or 22.55 billion total.