Komatsu Employs “Slick” Battery Swapping for Underground LHD

October 28, 2024

Ryan Gehm

Komatsu introduced its first battery-electric load-haul-dump (LHD) machine, the WX04B, at the MINExpo tradeshow in September. The WX04B is designed specifically for narrow vein mines in underground hard rock mining operations. Komatsu is pairing the electric LHD with its new OEM-agnostic 150-kW battery charger that was also revealed in Las Vegas.

The 4-tonne WX04B LHD features what Komatsu claims is best-in-class energy density, offering up to four hours of runtime on a single charge. The Li-ion NMC (nickel-manganese-cobalt) battery from Proterra has a capacity of 165 kWh and nominal voltage of 660 V. Fewer charge cycles are needed compared to competitors, the company claims, which helps to maximize operational efficiency and minimize downtime. Proterra and Komatsu began their collaboration on the LHD’s H Series battery system in 2021, long before Komatsu’s acquisition of American Battery Solutions (ABS) in December 2023.

Engineers focused on zero-harm, reliability and durability when designing the new WX04B, which features a proven reinforced boom, optimized Z-link geometry and Komatsu’s ROPS/FOPS-certified operator cab. An optional fully enclosed cab with environmental controls enhances operator comfort and safety. Interlocks automatically engage brakes and turn off all functions when the cab door is open or the seatbelt is disengaged.

Komatsu considers its first battery swap system a “standout feature” of the WX04B. Unlike many traditional systems that require extensive underground infrastructure, the WX04B’s battery swap can be performed at ground level without the need for cranes or rigging. The streamlined process is said to reduce costs and complexity, making it more efficient and user-friendly for underground mining operations.

“In the industry [battery swapping] is fairly common,” Brian Fox, senior VP of strategy and innovation for Komatsu Mining, told SAE Media at MINExpo. “But we’ve got a pretty slick system we’ve come up with.”

“One of the large differences [compared to other battery swap systems] is the fact that this has got no impact on mine infrastructure,” Brad Zimmerman, director of battery-electric technology for Komatsu Mining, told SAE Media at MINExpo. “Our battery swapping system allows for a high degree of misalignment, which isn’t the case for competitors that have got a similar system – the battery has to be very level, on concrete or a fixture or something to support the battery to keep it level. With this, it literally doesn’t matter – it can be below grade, above grade, misalignment this [side to side] way, and it’ll pick the battery up.”

It takes less than five minutes to swap a battery, he said. “Hard rock underground mining is adopting [battery-electric] at a wild pace because of the economics of the cost of air circulation – this actually saves them money,” Zimmerman shared. “I don’t know if that kind of financial upside is that strong in other industries. I know it is here, this is a no-brainer.”

The economics are even better for greenfield mines that are designed solely around battery-electric equipment, he added. “There are a couple of mines that I know of that have been seeing like 50% savings in operation costs. That pays for it [even though] it’s more expensive than diesel.”

Payback in that “perfect environment” of a greenfield mine can be two to three years, he said. “It’s really compelling.”

Vehicle-agnostic battery charger

Complementing the WX04B is Komatsu’s vehicle-agnostic 150-kW battery charger that has been engineered specifically for underground hard rock mining. The charger can be used with “almost any” battery-powered mining equipment that has a CCS2 connector, Zimmerman said. Its compact, rugged design allows the charger to be moved and deployed using standard equipment.

Key features include power efficiency, broad compatibility with mining power sources (400 VAC to 1000 VAC) and no need for an external transformer. A fully sealed enclosure eliminates the need for ventilation or liquid cooling. The design minimizes infrastructure requirements, offering mining operations greater flexibility without the need for a dedicated charging station, Zimmerman said.

“With the charging system, pick it up with a forklift, drop it off, it plugs into mine power, so the same electrical outlets that you would use to run a jumbo drill, or a face drill,” he explained. “And again, it can sit in the dirt. You can almost turn a little side drift in an underground mine into a charging station with no changes.”

The battery recharges in approximately two hours, which allows for better scheduling and reduced downtime on a vehicle that gets four hours of operating time. “Our plan when we’re looking at our forecasts is two batteries per machine,” Zimmerman said. “Until you get into a larger fleet situation, then you’re not going to have two exactly.”

The combination of the WX04B and the 150-kW charger highlights Komatsu’s efforts to offer a complete, scalable solution for the underground hard rock market. “These combined are an important benchmark for us in our journey to electrification underground,” Fox said.

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