In order to be able to replace the outdated vehicles of the West Berlin S-Bahn, the BVG had the class 480 developed in the 1980s. Due to the special requirements in Berlin, completely new vehicles had to be developed that could benefit from the latest technology. A 90 kW three-phase motor was used on all axles, which enabled faster acceleration with lower losses. The smallest unit is the so-called “quarter train”, which consists of two permanently connected vehicles, each with a cab. One to four of these are coupled together during operation.

Since the class 481 was developed for the entire Berlin after reunification, only 85 quarter trains were built. The trains were nicknamed “Toasters”. After the introduction of the newer vehicles, they were no longer used across the entire network. However, since they are still needed, they were modernized between 2015 and 2018. From 2020 they also received the BVG's new train control system.