FLIRT Akku
Keeping going when the catenary ends: the FLIRT Akku
Modern trains carrying lots of passengers do not have to run on diesel on routes without overhead lines: high-performance batteries can supply trains with high-speed and reliable power on non-electrified sections of the network. Stadler's battery electric multiple units (BEMUs) are designed for non or partially-electrified routes.
On sections with overhead lines, the trains powered by electricity can charge the batteries from pantographs and through regenerative braking. Where the contact wire ends, journeys can be continued in battery mode.
The FLIRT Akku, the battery-electric variant of the bestseller FLIRT and built in 2017, is Stadler’s first battery-powered train.
The vehicle concept is based on the well-established FLIRT electric multiple units and designed for operation under overhead lines. The FLIRT Akku is a single decker, lightweight aluminum train, which can be used in two or four-car trains. Like the FLIRT, it can be manufactured according to the customers’ needs and tailored to the network it will operate on. Multiple traction with purely electric single and double-decker vehicles is also possible.
Rail solutions to achieve net-zero.
How does a train run with a battery?
The FLIRT Akku is the battery-powered version of the FLIRT series, running either in the classic way with a pantograph under the catenary or in battery mode. State-of-the-art traction batteries are used instead of diesel engines on for short and medium-length journeys
Technical data (average)
Range in battery mode |
150 km |
Top speed |
max. 160 km/h |
Charging time under catenary |
15 minutes |
Seats |
120-180 |
Closing gaps on routes without catenary
In many countries, large sections of the rail network are not electrified. In Germany, for example, around 40 per cent is non-electrified. Eighty percent of these routes without overhead lines are 80 kilometres or less. The FLIRT Akku, which can replace diesel vehicles on branch lines without overhead lines, was developed to close these gaps.
FLIRT Akku prototype - world record holder via battery mode
Back in 2017, Stadler and the TU Berlin and EWE AG launched a research programme, funded by the German Federal Ministry for Economic Affairs and Energy. The aim was to develop and test the battery equipment for a multiple unit train that is carbon emission free on non-electrified routes. Although diesel trains are still in operation today, environmentally-friendly and energy-efficient vehicles can be used in future. The three-part prototype can carry 310 passengers and has 154 seats. The FLIRT Akku prototype is used for testing and trials are continuing in order to further develop the technology.
In December 2021, the FLIRT Akku set the world record for the longest journey with a battery multiple unit in pure battery mode, covering 224 kilometres. This was achieved despite the wintry conditions, snow and sub-zero temperatures. The accolade has been documented in the Guinness Book of World Records.