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.
NZR RM class (Edison battery-electric) battery-electric railcar was introduced as a faster and more desirable alternative. It ran between Little River and Christchurch twice each way each day, completing the journey in 69 minutes. The railcar was popular with both passengers and crews; it was fast for its time for a rural train on New Zealand's national rail network, and ran cleanly and efficiently. However, it lasted a mere eight years, as it was destroyed in a depot fire in Christchurch in 1934. Conditions created by the Great Depression meant it simply was not possible to build a replacement, and the Edison battery-electric railcar's legacy