The era of price wars in China’s electric vehicle (EV) market is giving way to a new contest: who can deliver better technology at the same price.On a cloudy evening in March, Shenzhen-based BYD put forward its answer with the unveiling of a battery capable of charging from 10 to 70 per cent in just five minutes – and to 97 per cent in nine minutes. The company said it would apply the technology to models priced as low as 155,000 yuan (US$22,500) while building 20,000 charging stations this year.In the audience, Zhang Sheng, a 55-year-old grocery store owner from…