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 supply or at a specially built recharging facility. From March 2014, a two-car battery electric multiple unit, the EV-E301 series with 1,500 V DC overhead wire and battery power capability, entered revenue-earning service on the long non-electrified Karasuyama Line. From April 2016, JR Kyushu started trial operation of a two-car BEC819 series BEMU train, nicknamed "DENCHA", on part of the Chikuhō Main Line, with revenue-earning service scheduled from October of the same year, and six more trains planned to be introduced on the line in spring 2017. It can also be powered via overhead AC power line. The BEC819 series