Can China, already the world’s biggest market for electric vehicles, get even bigger? With a mix of quotas and billions of dollars of state and private investment, the government wants one out of every five cars made and sold in China by 2025 to be electric. That would mean annual sales of seven million a year.

But the government’s ambitions could be stymied by something every smartphone user is familiar with: limited battery power. Unlike batteries in high-price U.S.-made Teslas, the batteries in most electric vehicles sold in China aren’t good enough to last, which limits electric cars’ potential popularity. That at least is the contrarian view of Dai Kun, the founder Uxin, one of China’s biggest used-car trading platforms.