Evaluation of 20000 km driven with a battery electric vehicle

The energy consumption and range of a battery electric VW Golf Variant are analysed in detail, using both dedicated tests and daily usage logs. The vehicle has been converted by the Dutch company ECE (Electric Cars Europe) into a battery electric vehicle. It is equipped with an AC Propulsion power train and Kokam lithium polymer batteries. Dedicated measurements are executed to analyse the energy usage as a function of the forward velocity and the contribution of auxiliary loads. During almost one year nearly all trips were logged, covering over 20000 km driven electrically. Trip length, outside temperature, battery state of charge and DC energy usage were recorded. Special attention is paid to recurring, fixed length commuting trips between home and work. They allow investigating seasonal variations, in particular the effect of the ambient temperature (-5 to 25 °C) on the vehicle range and energy usage in real life conditions. The results clearly show a decrease in battery capacity and increased energy usage at low temperatures, resulting in a major reduction of the vehicle range. Relatively simple computer models are already suitable to capture the energy usage for various driving conditions. The vehicle uses on average 25 kWh/100 km electricity from the grid.