Hitachi Construction Machinery has been working with ABB on developing a full battery dump truck since June 2021.
In March 2023, Hitachi signed a letter of intent with First Quantum Minerals to conduct feasibility trials of the prototype machine at the latter’s Kansanshi copper and gold mine.
Hitachi tested the basic operations of the prototype at its Hitachinaka-Rinko Works by gradually combining the battery charging and discharging system, pantograph, and other power supply systems with the drive system that controls the travel of the dump truck. After it was confirmed that all systems operate properly, the test machine was sent to the mining site in Zambia.
The technological feasibility trials, which are set to begin in mid-2024, aim to verify the basic performance of operations required of a dump truck, such as traveling, turning, and stopping under actual operating loads, as well as the battery charging and discharging cycles.
First Quantum already operates 41 Hitachi Construction Machinery diesel-powered trucks (39 of the EH3500AC-II and two EH3500AC-3 rigid dump trucks) in Kansanshi and already has much of the infrastructure required for full battery dump trucks in place.
The new truck uses an onboard electric system that draws energy from a trolley supply to power the motor directly as well as charging a battery energy storage system. Furthermore, when running downhill, the regenerative braking system charges the battery, which reduces the charging load when the truck is connected to the trolley. This enables the truck to stay in continuous operation with no charging breaks, to maintain high productivity, while a sophisticated battery energy- and thermal management system maximizes battery service life.
In operation on level ground the dump truck will run on its internal battery. While traveling uphill, it will draw power from the external trolley supply. Travelling downhill the truck will use energy recovered from regenerative braking to recharge the battery. This creates a virtuous circle that reduces the energy used by the dump truck.