Key takeaways
- Plus B means battery: the train runs electrically under the overhead line while charging, and runs off the battery without a contact wire.
- The distinguishing feature from the hydrogen variant is the pantograph – the Plus H has none.
- Roof containers are the giveaway compared with a pure electric Mireo without batteries.
- The target market is partially electrified lines where diesel railcars have run until now.
- Deployments follow tenders and infrastructure and change with timetable years – check the current picture.
Contents
Fact file
| Vehicle type | Battery electric multiple unit (BEMU) for regional services |
|---|---|
| Manufacturer | Siemens Mobility |
| Platform | Mireo – Siemens' regional multiple-unit family |
| Drive | Electric from the overhead line, from traction batteries on non-electrified sections |
| Meaning of the suffix | Plus B stands for battery, Plus H for hydrogen |
| Maximum speed | 160 km/h |
| Typical use | Partially electrified regional lines as a replacement for diesel railcars |
Identifying features
Is this really the class in front of you?
- A pantograph is fitted on the roof – unlike on the hydrogen variant
- Large roof containers for the traction batteries, clearly visible above the car body sections
- Mireo-typical nose shape with a large, deeply drawn-down windscreen
- No diesel exhaust, no radiator grilles in the side walls
- Runs on sections without overhead line, even though a pantograph is fitted
- Vehicle number begins with 94 – the UIC design code for electric multiple units
Updated: August 2026 – A multiple unit with a pantograph that nonetheless runs on lines without an overhead line: the Siemens Mireo Plus B is the battery variant of the Mireo platform, and one of the vehicles that shows how German regional services are being transformed. This page shows you how to identify it and how to tell it cleanly apart from the hydrogen variant and from a pure electric multiple unit.
Spotted a battery train?
New drive concepts often run in only small batches – noting the number and date is especially worthwhile.
What is the Siemens Mireo Plus B?
The Mireo Plus B is a battery-electric multiple unit for regional services, built on the Mireo platform from Siemens Mobility. Under the overhead line it works like an ordinary electric multiple unit while charging its traction batteries. When it leaves the electrified section, it lowers its pantograph and continues running off the battery.
That means the vehicle addresses a very specific problem: many German regional lines are only partially electrified. A pure electric multiple unit can’t get through there, while a diesel railcar unnecessarily runs the electrified sections on its combustion engine. The BEMU – battery electric multiple unit – closes exactly this gap.
Telling the Mireo family’s drive variants apart
Siemens supplies the Mireo platform in several drive configurations. The body shell looks almost identical across them – the difference sits on the roof.
| Variant | Pantograph | Roof structures | Runs without overhead line |
|---|---|---|---|
| Mireo (electric) | yes | flat, tidy | no |
| Mireo Plus B | yes | large battery containers | yes, on battery |
| Mireo Plus H | no | hydrogen tanks and fuel cell | yes, on hydrogen |
That gives you a two-question test that works practically every time: Is a pantograph fitted? And are large roof containers also fitted? Two yeses means a battery train. The Mireo Plus H has no pan, and the pure Mireo running as Class 463 / 464 has no battery containers.
Look from above if you can
With every vehicle running an alternative drive, the decisive information sits on the roof. A vantage point on a footbridge or a raised section of platform tells you more than any close-up of the front.
What you can observe in service
Battery vehicles make something visible that otherwise stays hidden: the transition between electrified and non-electrified infrastructure.
Look for the system-changeover point
That's where the overhead line ends. The train lowers its pantograph – often while rolling, sometimes at a stand. A process you can see on hardly any other regional train.
Watch for a charging stop
At some stations, charging is deliberately topped up under the contact wire. The train then stands for longer than would be needed just for boarding and alighting.
Listen for the sound
No diesel engine, no exhaust plume. An electrically starting train on a line without an overhead line is already a distinguishing feature in itself.
Note the number
The twelve-digit vehicle number begins with 94 and uniquely identifies the unit – important with small batches of only a few vehicles.
How the twelve-digit number is structured in detail, and what the individual blocks mean, is explained in the article on the UIC number. For a systematic approach to unfamiliar vehicles, the guide to identifying rolling-stock classes helps.
Follow new drive concepts live
Sightings from the community show you where battery and hydrogen vehicles are currently in service.
How a battery multiple unit works day to day
The concept behind the abbreviation BEMU is simpler than it sounds – and it explains why these vehicles look the way they do.
Under the overhead line, it’s an ordinary electric multiple unit. The pantograph sits against the contact wire, and the drive draws its power directly from the network. At the same time, part of the energy is routed into the traction batteries. So the train charges while running, without needing any standing time for it.
Without an overhead line, the battery supplies the power. The pantograph is lowered, but the drivetrain stays the same. From a passenger’s point of view nothing changes – no change of motor, no jump in sound, no exhaust plume.
Braking happens electrically wherever possible. When braking, the traction motor works as a generator and feeds energy back. Under the contact wire it goes into the network, without a contact wire into the battery. On lines with closely spaced stops, this share is considerable.
That gives rise to the design features you see on the vehicle: the batteries need space and cooling, which is why they sit in containers on the roof rather than under the vehicle floor. The pantograph remains essential, because without a contact wire there’s no charging either.
And that produces the operational logic: a BEMU is not a substitute for electrification but a gap-filler. It pays off when a sufficiently long section lies under the contact wire and the gap in between stays within the vehicle’s designed range. That’s why the deployment areas of such vehicles are never random – they follow the infrastructure.
Deployment, fleet size and what changes about them
With vehicles running alternative drives, this applies to an especially high degree: everything to do with operators, networks and fleet sizes is subject to change. Regional services are put out to tender, and with every award, vehicle deployment, keeper and livery can shift. Deployment also depends on infrastructure: without suitable charging infrastructure and a partially electrified line, a BEMU makes no sense.
What stays stable, on the other hand:
- The body design. Roof containers plus a pantograph remain the identifying feature, regardless of colour.
- The vehicle number. It stays with the vehicle even when operator or markings change.
- The design code 94. Even a battery train is, in the UIC system, an electric multiple unit.
Anyone wanting to know which vehicles are actually running right now works with live sightings and real-time data rather than network lists that can be out of date after every timetable change.
Safety at the platform edge
Electrically driven trains pull away quietly and approach more quietly than you'd expect. Keep a safe distance from the platform edge and don't step onto the track. Overhead line equipment carries high voltage – keeping your distance from masts, cantilevers and the contact wire is essential.
Common mix-ups
It points to a Mireo Plus B if …
- a pantograph is fitted
- large containers also sit on the roof
- the train runs on a section without an overhead line
- neither diesel sound nor radiator grilles are visible
Look more closely if …
- you can't see the roof – from below, all Mireo variants look alike
- another manufacturer supplies a similar battery concept
- the train is standing under the overhead line with the pan up
It's not a Mireo Plus B if …
- no pantograph is fitted – then the hydrogen variant comes into question
- the roof is flat and without containers – then it's a pure electric multiple unit
- a diesel engine is audible or radiator grilles are visible
Another realistic candidate is the Class 557 (CAF Civity BEMU): the same drive concept, a different manufacturer. Here the nose shape settles it, not the roof – because both have roof containers.
Conclusion
The Mireo Plus B is a vehicle you can identify from two observations: a pantograph fitted, battery containers on the roof. Everything else – range, network of deployment, fleet size – is project-dependent and changes with tenders and infrastructure. Anyone wanting to document it cleanly notes the vehicle number and doesn’t copy range figures second-hand.
In short
A pantograph plus roof containers, running even without an overhead line: that's the Mireo Plus B. The pan separates it from the hydrogen variant, the roof structures from a pure electric multiple unit.
Document the change of drive technology
Battery and hydrogen vehicles arrive in small batches. Whoever collects numbers and dates early ends up with unique material later.
Summary
- The Mireo Plus B is the battery-electric variant of Siemens' Mireo platform.
- It combines classic overhead-line operation with battery running on non-electrified sections.
- It's identified by the combination of a pantograph and large roof structures for the batteries.
- Where such trains run depends on tenders and how electrified the lines are, and changes constantly.
Frequently asked questions
What is the Siemens Mireo Plus B?
A battery-electric multiple unit based on the Mireo platform from Siemens Mobility. Under the overhead line it runs like an ordinary electric multiple unit while charging its traction batteries; on sections without a contact wire, it continues running off the battery. The maximum speed is 160 km/h.
What does the B in the type designation mean?
It stands for battery. Within the Mireo family, Siemens distinguishes several drive variants: Plus B denotes the battery train, Plus H the train with a hydrogen fuel cell. The body shell, interior concept and nose shape are largely the same across all variants – the difference lies on the roof and in the drivetrain.
How do I tell the Plus B apart from the Plus H?
By the pantograph. The battery train needs one to run under the overhead line and charge – so it has one. The hydrogen variant runs entirely from its own onboard energy store and manages without a pantograph. Both have roof structures, but only one of them has a pan.
How do I tell the Plus B apart from a standard Mireo?
By the roof structures. A pure electric multiple unit needs no traction batteries and accordingly has a flatter, tidier roof. On the Plus B, clearly visible containers sit there. A view from a bridge or a higher-up vantage point makes the difference obvious immediately.
How far can a train like this run without an overhead line?
The achievable range depends on battery size, topography, timetable, temperature and load, and is designed individually for each project. There's no universal figure that applies to every vehicle of this type – the only honest statement is that BEMU concepts are meant to close gaps in the electrified network, not to replace overhead lines altogether.
Does the Mireo Plus B replace diesel railcars?
That's the purpose. BEMU vehicles are procured where lines are only partially electrified and diesel railcars have run until now. Whether and when a particular network is converted depends on the relevant tender – that changes with every traffic contract.
Why does the vehicle number begin with 94?
Because 94 is the design code for electric multiple units in the twelve-digit UIC numbering system. It occupies the first two digits of the vehicle number. Battery trains fall under this too, because their drivetrain is electric – the energy source makes no difference to that.
Where can a Mireo Plus B be observed well?
At system-changeover points, meaning where an electrified line turns into a section without a contact wire. There the train lowers its pantograph – a process you can barely see on any other type of regional train. Which lines currently do this changes with the traffic contracts.
Log your sighting of the Siemens Mireo Plus B
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Related classes
Siemens Mireo Plus H
The Mireo Plus H is the hydrogen variant of Siemens' Mireo platform: fuel cell plus battery, no pantograph, used on lines without an overhead line.
EMUClass 463 / 464 (Siemens Mireo)
Classes 463 and 464 are the German numbers for the Siemens Mireo – two length variants of a modern regional multiple-unit family. Here's how to recognise them.
EMUClass 557 (CAF Civity BEMU)
A multiple unit with a pantograph running on a line without overhead wires: Class 557 from the CAF Civity family is a battery multiple unit – and that's exactly how you recognise it.
EMUNGT12 (Leipzig)
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EMUNGT12G
The NGT12G is a twelve-axle low-floor articulated railcar and one of the longer members of its family. The axle count in the name is the key to identifying it.
EMUNGT6D / MGT6D
NGT6D and MGT6D are six-axle low-floor articulated railcars of the first generation. The axle count in the name is also the quickest identification feature in the field.
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