IVL Swedish Environmental Research Institute was commissioned by the Transport Department and the Swedish Energy Agency investigated the lithium-ion battery climate impact seen from a life cycle perspective. It's the batteries intended for electric cars that were included in the study. The two authors Lisbeth Dahllöf and Mia Roman has done a meta-study, that is to say, gone through and compiled existing studies. The report shows that battery production leads to high emissions. For every kilowatt hour of storage capacity in the battery creates emissions of 150 to 200 kg of carbon dioxide equivalents, already at the factory. The scientists have not studied the individual car brands of batteries, how these particular produced or what electricity they use. But if we to an understanding of the importance of battery size takes an example: two common electric cars on the market, the Nissan Leaf and Tesla Model S, have batteries in about 30 kWh and 100 kWh.