BHP Weighs Charging Downtime in Pilbara Battery Truck Trial
Two Caterpillar 793 XE Early Learner trucks have been hauling at Jimblebar since June 2026. BHP's next question is how much haul-cycle time static charging takes away.
BHP is assessing the productivity impact of static charging on the two Caterpillar 793 XE Early Learner battery-electric haul trucks that began trials in June 2026 at its Jimblebar iron ore mine in the Pilbara, a project run jointly with Caterpillar and Rio Tinto.
BHP has moved its Pilbara battery-electric haulage programme past the question of whether the trucks work and on to the question that decides whether they get ordered in volume: what does stopping to charge do to the haul cycle?
The miner said in June 2026 that trials had begun at the Jimblebar iron ore mine with two Caterpillar 793 XE Early Learner trucks, run as a joint project with Caterpillar as the original equipment manufacturer and Rio Tinto as a fellow Tier 1 iron ore producer. The current phase is an assessment of the productivity impact of operating those trucks with static charging, as reported by International Mining.
Static charging is the variable that decides the business case
A diesel haul truck in a Pilbara pit is refuelled in minutes and otherwise runs. Its availability is set by maintenance, shift changes and queuing at the shovel and the crusher. A battery truck adds a new interruption: time parked at a charger, plugged in and not hauling.
Static charging means exactly that — the truck stops, connects to a fixed charging unit and takes energy while stationary. It is the simplest form of electrification to deploy, because it needs a charger, a power connection and a place to park, rather than overhead trolley lines strung along a ramp or dynamic charging infrastructure built into the haul road. The trade-off is that every minute at the charger is a minute the truck is not moving ore.
That is why BHP's stated focus on productivity impact matters more than a headline about zero-emission trucks. Haul fleets are sized on cycle time and availability. If a battery truck spends a materially larger share of its shift stationary than a diesel unit, a mine either accepts lower tonnes per truck or buys more trucks to hold output flat — which changes the capital arithmetic of decarbonisation before a single tonne of diesel is displaced.
Why two miners and one OEM are sharing the same pit
The Jimblebar work is unusual in that BHP and Rio Tinto, direct competitors in Pilbara iron ore, are running it together with Caterpillar. The logic is that neither miner gains an advantage from being first to learn how long a 793-class battery truck takes to charge on a working bench. The advantage comes later, in fleet pricing, charger standards and the pace at which a proven product reaches the market.
Early Learner units are pre-production trucks placed with customers to generate operating data in real conditions rather than on a test track. For Caterpillar, two trucks in the Pilbara hauling real ore against real grades and real queue times produce the kind of evidence that converts a demonstration into an order book. For the miners, the same data tells them whether to plan charging infrastructure around fixed points at the pit rim, around in-pit units that move with the mining face, or around something else entirely.
What the productivity numbers will actually determine
Three decisions hang on the outcome of this assessment phase.
- Fleet sizing. If charging downtime is material, replacing diesel units one-for-one will not hold production. The offset is either more trucks or faster charging.
- Infrastructure spend. Static charging is the cheapest starting point. If the productivity penalty is too large, the case strengthens for trolley assist or dynamic charging, which cost far more to install and tie a mine plan to fixed routes.
- Power supply. A charging fleet is a new electrical load in a remote pit. The size and timing of that load, which only operating data can establish, feeds directly into generation and grid planning in the Pilbara.
None of these are resolved by a trial that proves a battery truck can climb a ramp. They are resolved by shift-level data on how many tonnes each truck moves per day and what it costs to keep it charged.
How the three companies are trading
None of these are resolved by a trial that proves a battery truck can climb a ramp.
All three participants were higher in a firm session. As of the last trade at 13:55 GMT on 17 September 2026, BHP was quoted at 86.43, up 2.72% from the previous close of 84.14, in a day range of 85.64 to 86.56. Rio Tinto traded at 97.94, up 2.24% from a prior close of 95.79, with a range of 97.06 to 97.98. Caterpillar was at 804.63, up 2.80% from 782.72, having traded between 801.43 and 813.95.
The broad tape was supportive rather than the driver of anything mine-specific. The S&P 500 tracker (SPY) stood at $761.08, up 0.93%; the Nasdaq 100 tracker (QQQ) was at $715.08, up 1.47%; and the Dow tracker (DIA) was at $517.48, up 0.44%. A two-truck trial does not move a major miner's share price, and nothing in the day's moves should be read as a market verdict on battery haulage.
What would count as progress from here
The next meaningful disclosure is not another truck arriving at Jimblebar. It is a number: charging time per cycle, tonnes per truck per shift, or availability compared with the diesel units working the same benches. Until a miner puts figures like those in public, the industry's battery haulage debate stays qualitative.
Watch also for how the charging is configured as the trial matures. A shift from fixed chargers at a single location to units repositioned with the mining face would signal that static charging in its simplest form is costing more cycle time than the operators want to absorb. Conversely, an expansion of the Early Learner fleet at Jimblebar would suggest the productivity penalty is manageable at current charging speeds — and would be the clearest signal yet for Caterpillar's order pipeline.
Key facts
- Trial start: June 2026, Jimblebar iron ore mine, Pilbara
- Equipment: Two Caterpillar 793 XE Early Learner battery-electric trucks
- Partners: BHP, Caterpillar (OEM) and Rio Tinto
- Shares (17 Sep 2026, 13:55 GMT): BHP 86.43 (+2.72%); RIO 97.94 (+2.24%); CAT 804.63 (+2.80%)
Frequently asked questions
What is BHP testing at Jimblebar?
BHP is running battery-electric haul truck trials that began in June 2026 at the Jimblebar iron ore mine in the Pilbara, using two Caterpillar 793 XE Early Learner trucks. The current phase assesses the productivity impact of operating those trucks with static charging — that is, how much haul-cycle time is lost while a truck sits stationary at a charger.
What does static charging mean for a mining truck?
Static charging means the truck stops, connects to a fixed charging unit and takes energy while parked. It is the simplest and cheapest electrification approach because it requires only a charger and a power connection, rather than overhead trolley lines or in-road dynamic charging. The trade-off is that charging time is time the truck is not hauling ore.
Why are BHP and Rio Tinto working together on this?
BHP and Rio Tinto compete in Pilbara iron ore, but neither gains an edge from independently learning how a battery haul truck behaves in a working pit. Running the trial jointly with Caterpillar, the truck manufacturer, spreads the cost and speeds up the operating data both miners need before committing to fleet-scale orders and charging infrastructure.
What is a Caterpillar Early Learner truck?
Early Learner units are pre-production machines placed with customers so the manufacturer can gather operating data in real mining conditions rather than on a test track. For Caterpillar, data from two 793 XE trucks hauling real ore at Jimblebar helps validate the product and supports the case for converting trials into commercial fleet orders.
How did the three companies' shares trade on 17 September 2026?
As of the last trade at 13:55 GMT, BHP was quoted at 86.43, up 2.72% from a previous close of 84.14. Rio Tinto traded at 97.94, up 2.24% from 95.79. Caterpillar was at 804.63, up 2.80% from 782.72. Broad indices were also higher, with SPY at $761.08 and QQQ at $715.08.
What should investors watch next in this trial?
The key disclosures would be quantitative: charging time per haul cycle, tonnes moved per truck per shift, and availability compared with diesel trucks on the same benches. A change in how chargers are positioned, or an expansion of the Early Learner fleet at Jimblebar, would also signal how manageable the charging downtime is proving.
Sources
- BHP assessing productivity impact of battery truck use with static charging — International Mining
Photo: Magda Ehlers · Pexels Licence — source
