The advantages of electric traction are being opposed by the disadvantage that the associated infrastructure with power stations, substations and overhead lines is expensive to build and maintain. Especially when it comes to passenger transport on sparsely frequented secondary lines, it is often not worth building the infrastructure. This gave rise to the idea of storing the electricity required for the journey on the vehicle and recharging it again during stopsor overnight in the depot. The first big heyday of battery railcars began around 1900 and ebbed away again in the 1920s.
In Germany, the Pfalzbahn made the first attempts with battery-powered railcars in 1895. In the following years, other railways followed, some with converted passenger cars. From 1907, the Prussian State Railways procured large numbers of Wittfeld railcars, followed by the battery railcars of the Reichsbahn.
In other countries, the purchase of just a few copies was the norm. For example, in Italy, the Rete Mediterranea and the Rete Adriatica used a total of six battery railcars from 1898 and 1901, which were retired after a few years.
After the Second World War a series production of a significant number of battery railcars happened practically only in Germany. More than 200 power cars of the types ETA 176 and ETA 150 were built. In Great Britain, apart from a test set called BEMU (Battery Electric Multiple Unit), there were only ten class 419 mail railcars, which only used the batteries to cover short sections.
In the 21st century, a new era of battery-powered multiple units began, which are now being built primarily for environmental reasons and are intended to replace diesel-powered vehicles. With advances in the development of battery technology, construction of various models began in Japan around 2010. Almost 30 sets of battery-powered multiple units are now in commercial use there. In Europe. the first types were only presented in 2018. In the meantime, the first sets have been ordered here from Bombardier/Alstom, Siemens, Stadler and CAF or are being tested.
While earlier battery railcars rarely reached 60 mph or 100 km/h and had a rather modest acceleration, the development goal today is to achieve values in acceleration and top speed which correspond to modern electric commuter multiple units. Due to the limited battery capacity, it is not yet possible to run for several hours without an external power supply. In the models developed to date, the batteries are primarily used to cover sections of up to 60 miles or 100 km in length that are not equipped with an overhead line. The batteries can then be recharged via the overhead line in the electrified section while driving. In Japan in particular, short pieces of catenary are also used, under which the train is charged during a stopover.