Article published ELECTRIC VEHICLE MONITORING
Batteries offering improved performance and greater strength
This platform prepares and carries out tests on the behaviour of batteries for electric vehicles, under actual conditions of use, to ensure their compatibility with the stringent cost and performance requirements of the automotive sector. Improved performance is the goal.
CEA LITEN launched its electric vehicle monitoring platform at the beginning of 2009 to meet the need for improved battery performance and charge life. The platform prepares and carries out tests on battery behaviour and energy consumption, under actual conditions of use, with the help of many miniature sensors that are invisible to the driver and located in various parts of the vehicle. Many parameters are measured during the tests - voltage, current, electrical energy, temperature, speed, GPS-based road profiles and so on. The data obtained is analysed and compared by the information technology unit, then correlated with reference values to deduce electric drive system performance. In order to highlight the progress made by electric batteries in the past twenty years, the platform installed test instruments on an electric version of a Citroën AX running on NiCd batteries and compared it with the same vehicle, equipped with a pack of new-generation lithium iron phosphate batteries in innovative assembly configurations. For built-up areas, the study showed the old version to have a range of 60 to 100 km. The new version had a range of 80 to 120 km, with batteries half the weight and volume (138 kg and 85 litres). Other projects are underway in partnership with Aixam, Michelin, Toyota and Irisbus, as part of the French Environment Round Table initiatives. The projects concern twenty vehicles and tests are performed on roads in cities, periurban areas and in the mountains around Grenoble. At the same time, the parameters of electric drive system components are characterised directly on an electric motor test bench (engine power, gears, battery packs, etc.), before undergoing road tests under “real conditions”.
