Since the eight prototypes of the ETA 176 series proved themselves, their development as the ETA 150 was built in series from 1954. Externally, the production vehicles not only differed from the ETA 176 in terms of the revised front end, but also in terms of their conventional buffers and screw couplings. This meant that conventional passenger or freight cars could also be carried, while the predecessors could only be coupled to the specially made control cars.
Since the ETA 150 only had a driver's cab on one side, 216 control cars were built to go with the 232 motor cars. With 23.40 m, they were shorter than their predecessors and were delivered with different layouts of the passenger compartment, which had a different number of seats in first and second class. The traction motors now each had 150 instead of 100 kW. In the course of production, larger and larger batteries were installed, which were exchanged for the largest available model every four years. Depending on the route, the range was between 250 and 400 km. Since the high weight of the battery hung between the bogies, the car bodies sagged over time, which led to the nickname “Hängebauchschwein” (pot-bellied pig).
Over time, the vehicles deployed in significant numbers received several nicknames, such as “Whistle Buoy” or “Maya the Bee” referring to the running noise. Otherwise, they were also called “Battery Flash”, “Acid Bucket”, “Socket Intercity” and “Flashlight Express”. They were used almost exclusively on flat land to prevent the batteries from draining too quickly. From 1968 the motor cars were redesignated as the class 515 and the control cars as the class 815. From the 1980s onwards, they were mainly replaced by class 628 diesel railcars and were completely phased out by 1995.