Modular Lithium Batteries for Electric Dumpers and Off-Highway Construction Machinery

The electric evolution of off-highway machines in the construction sector

Urban job sites and increasing sustainability requirements are driving the demand for low-emission, low-noise machines with reduced environmental impact. As a result, the electrification of dumpers, excavators, wheel loaders, and other off-highway vehicles is becoming a strategic priority for manufacturers.

However, these machines often operate under extremely demanding conditions: dusty environments, intensive duty cycles, and remote or temporary locations where access to the electrical grid is limited or unavailable. Ensuring operational continuity requires flexible, modular energy solutions that can adapt to different job site needs.

The main benefits of electrification include:

• reduced emissions and noise
• lower total cost of ownership (TCO)
• reduced maintenance requirements
• improved operational reliability

To address these challenges, Flash Battery developed a modular solution capable of powering machines of different sizes, minimizing variants and simplifying integration. This is made possible thanks to extensive expertise in off-highway electrification and a highly customized design approach.

Designing a range of electric dumpers with a modular energy architecture

The project began in 2023, when Fiori Group, an international construction equipment manufacturer decided to fully electrify its first product range. The starting point was a dumper designed to operate in demanding conditions, selected as a pilot model to test energy solutions that could later be extended across the entire range of full electric and hybrid machines.

The objective was clear: design a modular and scalable energy architecture from scratch, capable of adapting to machines of different sizes and power requirements without developing a dedicated battery for each model. This strategic approach reduces engineering complexity, optimizes production, and ensures technological consistency across the electrified range.

To tackle such a structured project, the manufacturer partnered with Flash Battery, initiating a co-design process aimed at defining the architecture of the next generation of electrified machines.

Modular batteries for full electric and hybrid machines: the challenge of off-grid job sites

From the early stages, a key challenge emerged: ensuring autonomy and operational continuity even in job sites without access to the electrical grid. This led to the need for a solution compatible with both full electric machines and hybrid versions equipped with an onboard generator.

The customer defined the following key requirements:

• only two voltage levels: 51.2V and 102.4V
• modular architecture with 1 to 4 batteries connected in parallel
• compatibility with both full electric and hybrid machines
• ability to recharge via onboard generator

This last requirement represented one of the most complex challenges. In off-grid environments, battery charging cannot rely on charging stations but must be managed through an onboard generator. This introduces very different conditions compared to grid charging, making high-power cell balancing essential to ensure proper cell equalization and accurate state-of-charge estimation.

To meet these requirements, a fully custom, modular, and integrated solution was developed, leveraging Flash Battery’s proprietary technology to ensure autonomy, reliability, and operational continuity in both full electric and hybrid applications.

Modular LFP lithium batteries: a scalable solution for off-highway machines

The project resulted in the development of two lithium battery models based on LFP (lithium iron phosphate) chemistry. Both can be used individually or configured in parallel up to four units, allowing easy adaptation of energy capacity to different machine sizes and applications.

• 51.2V from 11 to 47 kWh
• 102.4V from 23 to 94 kWh

The choice of LFP chemistry was driven by the need for safety, thermal stability, and long service life, all critical factors for machines operating in harsh environments such as construction sites.

The modular architecture is designed to use the same modules as building blocks, which can be combined in parallel to create different configurations while maintaining a single technological platform.

Key design features include:

• custom firmware for generator-based charging management
• advanced cell balancing algorithms
• CANbus integration with the vehicle control system
• IP65-rated enclosure
• HV and MSD safety systems
• charging capability via onboard or off-board chargers for faster charging

Flash Battery’s structured approach: from consulting to co-design for construction OEMs

In a project like this, the battery is not just a component, it becomes a structural element of the machine’s architecture.

For this reason, Flash Battery supported the customer from the earliest stages, adopting a co-design approach capable of transforming requirements into a concrete, reliable, and industrialized solution.

Starting from a blank sheet, the joint work between Flash Battery’s technical team and the manufacturer led to the definition of the energy system for the new machine range, including operating voltages, modular design logic, and battery sizing criteria.

Flash Battery’s contribution was particularly critical in:

• defining a scalable and adaptable modular battery architecture
• optimizing integration between the battery and the control system
• developing dedicated firmware logic for different operating modes
• ensuring overall system safety and reliability

Special attention was given to the hybrid version, which requires continuous interaction between battery, generator, and vehicle control system. To address this, dedicated firmware logic was developed, enabling the Battery Management System (BMS) to communicate directly with the machine and correctly manage charging cycles even under non-standard operating conditions.

This integrated and forward-thinking approach strengthened the collaboration, positioning Flash Battery not just as a supplier, but as a technology partner in the electrification of the new machine range.

Benefits of lithium batteries in electric dumpers and construction machinery

The introduction of these new batteries enabled the customer to launch not just a single electric model, but an entire range of electrified machines, with an immediate and significant commercial impact.

Key benefits include:

• access to job sites and tenders requiring low-emission machinery
• improved efficiency thanks to the shift from hydrostatic to electric traction, reducing TCO compared to diesel machines
• full work cycles ensured by the batteries, without compromising performance
• greater flexibility in machine configuration thanks to the modular energy system

One particularly interesting market insight concerns the hybrid version, which is experiencing strong demand. This configuration represents a true “technology bridge”: operators benefit from electric traction while maintaining the ability to recharge via generator when grid access is not available.

Today, this project stands as a concrete example of how off-highway electrification can be successfully achieved through co-design between OEMs and technology partners, transforming a complex technical challenge into a scalable energy system ready for the future of construction machinery.