Danfoss Validates Dextreme Max System for Electric Excavators

Danfoss Power Solutions has announced the validation results of its Dextreme Max system following testing in a 30-tonne battery-electric excavator. Supported by a £4.29 million grant from the UK Government’s Red Diesel Replacement Phase 2 Competition, the project demonstrated that Danfoss’ digital hydraulic architecture reduced excavator power consumption by 35% across a representative duty cycle, extending runtime by 53% on a single charge.

The Dextreme Max system is engineered to reduce energy consumption by up to 50% by mitigating energy losses and recovering energy during machine operations. The core of the system is the DDP180D, a Digital Displacement hydraulic pump/motor featuring multiple independently controlled outlets. This architecture provides independent actuator supply, eliminates flow-sharing losses, and enables energy recovery from motions such as boom lowering.

Danfoss

Machine Configuration and Engineering

For the validation, Danfoss utilized a Develon DX300LC-7 crawler excavator. Originally a diesel-powered machine, it was converted to an electric configuration by Staad B.V. The electric drivetrain included a Danfoss Editron permanent magnet synchronous motor, inverter, and motor controller, supported by three 140-kWh batteries.

Danfoss engineers replaced the machine's conventional swashplate hydraulic pump with the DDP180D pump/motor. The excavator’s four primary services—boom, arm, bucket, and swing—were supplied through 10 individually controllable outlets on the pump. These outlets are dynamically grouped via a ganging block, a digital distributor that reallocates capacity to the services requiring it in real-time.

Furthermore, a dedicated hydraulic H-bridge valve was developed for the boom function to allow independent metering, providing pressure amplification and energy recovery during overrunning motions.

Danfoss

Performance Results

To benchmark the system, Danfoss conducted multiple tests, including JCMAS air grading and JCMAS air dig and dump. When compared to the baseline electric excavator, the Dextreme Max system achieved:

• 49.2% reduction in battery energy use during air grading.
• 31% reduction in battery energy use during air dig and dump.

Based on a duty cycle mix of 30% grading and 70% digging, the system reduces battery power consumption by 35% with negligible impact on cycle times. This efficiency allows for 53% longer operating hours with the existing battery capacity, or the potential to achieve standard runtimes using two battery packs instead of three.

“The results of this testing highlight the potential of digital hydraulic architectures to overcome the obstacles in heavy-duty machinery electrification,” said Alasdair Robertson, Senior Director, Digital Displacement, Danfoss Power Solutions. “Electric excavators offer excellent responsiveness, smooth control, a quiet cab environment, and zero-emission operation. With Dextreme Max, they can also deliver the runtime, productivity, and total cost of ownership advantages required for wider adoption.”

Path to Commercialization

The Dextreme Max project was funded as part of the UK Department for Energy Security & Net Zero’s £1 billion Net Zero Innovation Portfolio, which seeks low-carbon alternatives to red diesel for the construction and mining sectors.

Danfoss offers its Dextreme systems through an incremental implementation approach:

• Dextreme Swap — A pump replacement offering improved control and efficiency.
• Dextreme Flex — Flexible allocation of pump outlets to reduce distribution losses.
• Dextreme Max — Full integration including energy recovery and independent metering.

While the Dextreme Swap and Flex systems are already commercially available, this project serves to advance the commercial path for the Dextreme Max configuration.