Trough battery spaces between the plates (the troughs) were filled with dilute sulfuric acid. So long as the box was not knocked about, there was no risk of electrolyte spillage. Trough battery The trough battery was a variant of Alessandro Volta's Voltaic Pile and was invented by William Cruickshank c. 1800. Volta's battery consisted of brine-soaked pieces of cloth sandwiched between zinc and copper discs, piled in a stack. This resulted in electrolyte leakage as the weight of the discs squeezed the electrolyte out of the cloth. Cruickshank solved this problem by laying the battery on its side in a rectangular box.
Battery electric multiple unit battery/electric trains became operational on the through services on the Fukuhoku Yutaka Line in October 2016, which is electrified at 20 kV AC and the non-electrified Chikuhō Main Line, known as the "Wakamatsu Line", between Orio and Wakamatsu. A new EV-E801 series two-car BEMU train was introduced on the long non-electrified Oga Line in Akita Prefecture in March 2017. This differs from the earlier EV-E301 series train in being recharged from a 20 kV AC overhead supply instead of a 1,500 V DC overhead supply. Auckland Council has purchased 17 battery/electric trains from CAF in Spain, to operate between Britomart