
The new Battery Electric Power Unit (BEPU) from Caterpillar is a plug-and-play solution that can directly replace a diesel CAT engine in existing machines – occupying the same space, and even using the same motor mounts to make the conversion from diesel to electric (almost) as easy as swapping an engine.
First shown as a prototype at the IFAT equipment expo in Munich, Germany earlier this month, Caterpillar‘s BEPU has already proven to be more than “just a concept” by finding a home inside one of Doppstadt’s SWS 6 Spiral Shaft Separators in a working quarry operation.
“This is an exciting trial of an electrified variant of their SWS 6 Spiral Shaft Separator, which delivers zero-exhaust emissions and low noise when in operation,” explains Andy Curtis, Customer Solutions Director at CAT Industrial Power Systems. “The CAT BEPU has enabled the rapid development of this option alongside their diesel variant, with minimal engineering effort. Its intermittent duty cycle, suitability for indoor use, and access to low-power grid energy make the BEPU an ideal fit, with an on-board battery buffering simplifying energy management for end users.”
BEPU integrates a high-torque electric motor, inverter, onboard charger, cooling system, battery controls, and energy storage into a single, compact, cubular unit (copyright Jo Borrás, 2026), making it just as straightforward for engineers and CAD operators to package BEPU into new equipment designs as a conventional CAT diesel engine.
Making electrification easy

Caterpillar calls BEPU “a true drop-in solution” that allows manufacturers to standardize on a single machine architecture while offering powertrain options tailored to application needs. Because it fits wherever existing CAT diesel engines are currently used, BEPU removes the need to develop separate ICE and battery-powered platforms. It also answers many of the engineering, parts procurement, and service and support questions that brands without Caterpillar as a powertrain partner may still have when it comes to electrifying their equipment.
In other words: if you can design a machine around a CAT diesel engine, BEPU will fit where that engine goes and you can probably squeeze some batteries in where the fuel tanks would have gone (and Caterpillar can probably sell you those, too).
No word yet on pricing and broader market availability, but stay tuned – some ideas are simply too good to stay pilots for long.
SOURCES: Caterpillar, Doppstadt.

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