If a sign of a good idea is that it never quite dies, battery swapping for EVs is a good idea. Nio Inc, a struggling Chinese start-up, and the Chongqing Changan Automobile Company, a thriving EV maker, have signed an agreement to cooperate on battery swapping among other things, building on a pledge Nio made in February to build more than 1,000 swapping stations in China this year. That is more than double its initial target and in addition to 2,000 stations it’s already built. Swapping batteries is supposed to remove consumer anxiety about range, because it takes no longer to swap than to refill with petrol, and battery degradation – because your battery is always more or less good as new, and in any case is not your problem; Nio’s battery business model is to lease batteries as a service rather than sell them. The trouble is that swapping has engineering requirements that most big manufacturers have decided to ignore in favour of built-in battery packs that users have to charge. In the early years of its Zoe and Leaf EVs, Renault-Nissan joined forces with an Israeli swapping start-up with ambitions to transform the industry. They came to nothing. Nothing daunted, Nio’s next frontier is Europe. Bloomberg has the scoop.