A comparative range approach using the Real World Drive Cycles and the Battery Electric Vehicle

In the UK, a quarter of all CO2 emissions come from transport and 90% of this comes from road vehicles. According to the UK Government (a) at the end of 2013 there were 35 million vehicles licensed for use on the roads of UK and during 2013, over 4300 new ultra-low emission vehicles (ULEV - vehicles with emissions of CO2 below 75 g/km, or fully electric) were registered for the first time, this is 25% up on 2012. This included over 3600 cars and vans eligible for UK government `plug-in grants' this statistic is nearly 50% more than in 2012. Renault Zoe and the Nissan Leaf were the most popular electric vehicles available to the European market. The purpose of this drive cycle research work is to give the BEV (Battery Electric Vehicle) user an indication of the realistic range that the vehicle can travel without encountering a depleted battery and resulting in vehicle electrical system failure. This is the greatest concern to the user of this technology. In the present work it has been found that the predicted residual mileage (available range) of BEVs can be up to 22% short of what the battery can deliver. There are many mitigating factors and algorithms that are combined to give the driver of the battery electric vehicle an indication of the `distance to empty' as displayed on the car dashboard and this paper will compare the NEDC (New European Driving Cycle) with the dashboard estimation and the Real World Drive Cycle for a range of different routes and drive conditions. If the vehicle is driven in extreme winter conditions then the range could more realistically be reduced by 50% for an average suburban trip when compared with the NEDC figures. This study will address the `range anxiety' discussion that is often voiced when offering the BEV as an alternative to the conventional fuel vehicle [1].

Legislative Range Testing

The NEDC test is a standard European measurement of emissions and consumption based on a rolling road test. It is the same standard for petrol and diesel engines as it is for Battery Electric Vehicle. It is a recognised and objective way to measure the performance gaps between competition models and changes in specification. The car is landed on a rolling road dynamometer, undertaking the same urban cycle (ECE-15 cycle) three times, then undertaking the extra-urban cycle once. The average of these 4 cycles decides the NEDC range.