BUSCH + MÜLLER USB-Werk Dynamo USB Bike Charger – 5V 500mA

Intro

The USB-Werk by Busch + Müller is a dynamo-powered USB bike charger, designed for simple and reliable power supply on everyday rides and light touring.

It delivers a fixed 5V output up to 500mA, with an integrated buffer battery that ensures stable charging even at low speeds or during short stops.

Real-world performance

The USB-Werk is built for consistency, not peak output.

• steady power supply for GPS and low-consumption devices
• smartphone charging possible, but slow → best for maintaining charge
• stable output despite speed fluctuations

The internal buffer battery smooths interruptions when slowing down or stopping. This is a minimal, dependable power solution, not a high-output charger.

What it is and who it’s for

What it is
A USB charger powered by a hub dynamo, with fixed 5V output and integrated buffer battery.

Who it’s for

• daily commuting
• light touring setups
• riders who want a simple, no-adjustment system
• basic dynamo configurations

If you want plug & play reliability, this is the most straightforward option.

Positioning within the B&M range

• USB-Werk → simple, fixed output, plug & play
• K-Werk → adds powerbank functionality
• E-Werk → adjustable, higher output, advanced setup

The USB-Werk sits at the entry functional level: simple, effective, no tuning required.

Limitations (transparent)

• max output 500mA → not suitable for fast charging
• limited compatibility with some lights (e.g. IQ-X)
• part of the dynamo power is used to recharge the internal battery
• internal battery discharges even when no device is connected

Used in the right context, it’s reliable. Used outside it, it feels underpowered.

FAQ 

Can it charge a smartphone?
Yes, but slowly. It’s better suited for maintaining battery level rather than fast charging.

Does it work at low speeds?
Yes, thanks to the internal buffer battery that stabilizes output.

Do I need a specific dynamo hub?
It works with most standard hub dynamos.

Is it waterproof?
It is splash- and rain-resistant, suitable for everyday riding conditions.

CTA

Not sure if this is enough for your setup, or if you need more output?

Get in touch with Bikejamming — we’ll help you choose between USB-Werk, K-Werk and E-Werk based on real-world use.

Technical specifications

• Power source: hub dynamo
• Output: 5V / up to 500mA
• Battery: integrated buffer battery
• Port: USB output
• Protection: splash- and rain-resistant
• Dimensions: 30 × 35 × 15 mm
• Weight: 47 g
• Material: plastic
• Certification: StVZO approved
• Use: commuting / light touring / sporty bikes

Build & compatibility

• compatible with standard hub dynamo systems
• includes output cable with USB socket
• limited compatibility with some Busch + Müller lights (e.g. IQ-X)
• easy mounting on bike frames