48 required performance, energy density, cycle life and charging needs. LTO is well suited for intensive duty cycles, while LFP offers strong safety and cost advantages; NMC and NCA are options when higher energy density is needed.” Duty cycle significance The duty cycle and power profile are related concepts that apply to all machinery, and it is critical to pay attention to them in the design of vehicles with smaller energy budgets than those running on hydrocarbon fuels. The duty cycle describes what happens and when, while the power profile quantifies how much power is needed to make it happen. Both also differ significantly between classes of off-highway vehicle. From an engineering perspective, the power profile provides invaluable information for specifying the motor and the battery (or fuel cell stack), for design of the cooling system and for evaluating the viability of electrifying the task. The motor of a wheel loader, for example, must be sized to deliver the torque and power to meet the high peak power demanded by the pile ramming and digging phases without overheating. That peak power demand also determines the C-rate required of the battery, while the total energy consumed for a complete duty cycle is calculated by finding the area under the power profile curve. The two major heat-generating events (digging and lifting) are also identified from the power profile, while the duty cycle reveals their duration and frequency and provides the information needed to gauge the capacity requirement for the thermal management system. While the repetitive high peaks in power demand are challenging for both battery and motors, the consistent cycle with regular periods of lower demand provides opportunities for them to cool down. Equally important as the selection of cell chemistry are ruggedisation and serviceability, both of which play major roles in how the battery pack is designed or selected, he says. Shock, vibration, ingress protection and structural robustness are critical, and to address these issues, the company combines multiple layers of validation. “Balancing ruggedisation with serviceability is a key design trade-off. The pack must be robust enough to withstand harsh operating conditions while still allowing safe and efficient maintenance by aftermarket personnel,” Nedjimi emphasises. “We place importance not only on accessibility of service points but also on ensuring that commissioning and decommissioning procedures can be executed safely, with minimal downtime.” With charging, the direction of travel is from slow AC systems to highpower DC fast charging on fixed sites, including depots, farmsteads, sawmills and log yards with established grid infrastructure. While AC is well suited to overnight charging of machines with relatively small batteries, such as compact excavators, high-power DC systems are essential for large excavators and haul trucks that must be recharged over a lunch break, for example, so the industry is standardising on chargers rated from 150 kW to more than 1 MW. Charging ecosystem Volvo CE sees charging as an integral part of the e-mobility ecosystem rather than as a separate element, according to Nedjimi, and stresses the need to support vehicles that cannot return to a central depot. This involves compatibility with existing infrastructure, offering its own chargers and providing solutions for locations without grid access, and compatibility is critical. “Because charging protocols and connector standards vary across regions, our priority is to ensure that all machines can interface with the appropriate inlet types used in each market.” Most of its chargers rely on standard protocols, but the segment below 60 V that Volvo CE’s ECR25 and L25 inhabit is not served by a universal standard. So, it developed a proprietary communication protocol, publishing it to help drive alignment across the industry and to help create a more unified ecosystem. The company also continues to consider alternative charging strategies such as battery swapping, he notes, adding that this requires careful consideration around standardisation, safety and operational logistics. “We are actively evaluating modular and swappable energy solutions for applications where uptime and operational flexibility are critical. This includes the possibility of standardised mobile battery packs, but our strategy extends beyond simply swapping batteries on the machine. Digest | Volvo Construction Equipment January/February 2026 | E-Mobility Engineering The L25 compact wheel loader is powered by a 48 V multi-pack modular battery system with up to 40 kWh that provides enough energy for a full working day
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