On July 21, CATL, China's largest automotive lithium-ion battery maker, formally sued its smaller rival CALB for patent infringement.

In the first half of this year, CATL's installed capacity was nearly 8 times that of CALB, so how did CALB, which seemed to have no threat to speak of, "pissed off" CATL? Perhaps we can find out the real reason from customer purchase orders.

In 2019, CATL and CALB supplied 1,136.56 MWh and 595.34 MWh of batteries to GAC passenger cars, respectively, and the former was nearly twice as much as the latter, 21jingji.com reported on Wednesday.

The situation reversed in 2020, with CALB's installed capacity for GAC passenger cars reaching 2,033.65 MWh and CATL shrinking to 824.69 MWh, the former was nearly 2.5 times that of the latter.

In the case of GAC Aion, for example, 30 of the 63 vehicle models declared by the brand in the first half of 2020 had CATL as the battery supplier.

But in the second half of the year, CATL was no longer present in any of GAC Aion's newly declared models.

In the latest batch of recommended new energy vehicle catalogs from the Chinese Ministry of Industry and Information Technology, GAC Aion has not declared a model with CATL batteries for 12 months in a row, but CALB is still listed.

This was also the case at Changan Automobile, where CALB supplied 785.44 MWh to Changan in 2019, surpassing CATL's 592.43 MWh.

In 2020, CALB was well ahead of CATL's 109.3 MWh with 459.21 MWh installed in Changan's battery demand, widening the gap even further.