Electrical engineering credited with establishing the term "electricity". He also designed the versorium: a device that detects the presence of statically charged objects. In 1762 Swedish professor Johan Carl Wilcke invented a device later named electrophorus that produced a static electric charge. By 1800 Alessandro Volta had developed the voltaic pile, a forerunner of the electric battery In the 19th century, research into the subject started to intensify. Notable developments in this century include the work of Georg Ohm, who in 1827 quantified the relationship between the electric current and potential difference in a conductor, of Michael Faraday (the discoverer of electromagnetic
Battery electric multiple unit electric units have a higher purchase price and running cost than petrol or diesel railcars, needing one or more charging stations along the routes they operate. Battery technology has greatly improved over the past 20 years broadening the scope of use of battery trains, moving away from limited niche applications. Despite higher purchase and running costs, on certain railway lines battery trains are economically viable as the very high cost and maintenance of full line electrification is eliminated. From March 2014 passenger battery trains have been in operation in Japan on a number of lines. Austria and New Zealand have