Nowadays, politicians are forced by air pollution prevention to demand zero emission vehicles (ZEV) in the form of pure electric vehicles. The poor capacity to weight factor of actual batteries compared to any kind of liquid or gaseous hydro-carbon fuel is the main reason for the retarded implementation of ZEV.
Solutions offered by automobile manufacturers are mild to full hybrid powertrains based on the well established ICE platform. The difficulty of those approaches of electrification is to compete with the performance and benefit costumers expect from standard automobiles. Pure electric vehicles are rare and often disappointing regarding range and/or performance. Additionally the costs for such vehicles, which are mainly driven by the battery prices, are comparatively high, impeding their market entrance and acceptance.
Low price electric city scooters are actually offered as pure electric vehicles in a wide variety of different models. The category of city scooters (L1e [1]) is regulated regarding limited speed and engine capacity. The driving distance is generally short and additional comfort features (such as heaters or air condition) are not expected nor demanded by the customers.
The selling numbers of electric city scooters are strongly depending on the local legislation. In case of the establishment of restricted areas with exclusive access for zero emission vehicles, their share will be positively affected due to the capability of pure electric driving. The only disadvantage is range distance uncertainty due to the small battery size of such economic vehicles.
This can either be improved by increasing the battery capacity (negative influence on costs) or by implementing a Range Extender technology (greening influence) with a simultaneous decrease of the battery size. A small combustion engine with a generator, loading the batteries in case of long distance driving, is required.
The analysis of existing electric scooters and the theoretical implementation of a small Range Extender in a simulation model (via PHEM [2] MATLAB, and MS Excel) of a scooter are able to assess the application of Range Extender technologies in electric scooters for standard driving cycles. Additionally, decisions concerning engine and generator have to be made as well as careful considerations on packaging, costs, weight, economics and other ecological factors. Finally, the presentation of a draft design of a Range Extender package demonstrating its potential completes this study.