There is a simple concept that can significantly improve the environmental balance of battery electric vehicles and at the same time avoid the known disadvantages of these vehicles (short range, long charging times, high acquisition costs) without having to wait for further developed batteries or a higher proportion of green electricity. For this purpose, the vehicles are equipped with built-in batteries for short and medium distances and are therefore sufficient for the majority of daily journeys. For long-distance journeys, the driver borrows charged additional battery packs at swapping stations, which are automatically inserted into a standardised exchange slot within a few minutes. This paper focuses on the improvements in electric vehicles that can be achieved by combining built-in and exchangeable battery technique and also on the practical feasibility of the concept. It is shown that the battery capacity required for the entire vehicle fleet can be significantly reduced. The resulting ecological advantages on the one hand and grid-stabilising effects of a nationwide network of swapping stations on the other hand, support the transition to environmentally sustainable mobility. The characteristics of the concept presented are advantageous for its practical implementation. The acceptance by customers and manufacturers can thus be improved compared to previous battery swapping systems. The loan system for the exchange batteries may be designed conveniently and information security as well as data protection will be strictly complied.