Sandvik’s Toro LH518iB battery-electric loader just wrapped up roughly ten months of trial at Codelco’s El Teniente mine in Chile, and the OEM says it hit its performance targets. Before anyone starts drafting the obituary for diesel underground, let’s look at what actually happened — and what didn’t.
Here’s what this really means: one loader, one mine, ten months, running alongside six automated diesel Sandvik loaders on the same transfer level, under the same conditions, with AutoMine automation. That’s the entire sample size. The machine integrated into day-to-day operations and met its production requirement. That’s genuinely useful data — and it’s a trial, not a revolution.
The numbers worth noting: mechanical availability of approximately 87%, no safety incidents tied to Sandvik’s maintenance delivery during the evaluation period, and battery performance that kept pace with the production cycle. Each battery delivered an average of five hours and twenty minutes of effective operating time, with swaps completed in under five minutes. Battery service supported operating continuity without energy-related delays.
Now, 87% mechanical availability — is that good? For an underground loader, it’s respectable, not spectacular. Diesel fleets at mature operations can push higher. This isn’t the first time we’ve seen this circus: a vendor runs a pilot with its best engineers on site, hands on the machine, and full attention from both parties, then the press release reads like the technology is production-proven at scale. Sandvik had specialists in maintenance, automation, reliability and remote monitoring embedded in this program, with support from Camarillo and Turku. Ask yourself what availability looks like when the vendor’s A-team goes home and a mine’s regular maintenance crew is turning the wrenches at 800 meters depth. That’s the number that matters, and nobody’s publishing it yet.
That said, I’ve been skeptical of battery-electric underground equipment for a decade, and I’ll concede the trend line is real. Ten years ago the pitch was all promise and no duty cycle. Today we have a large-format loader — the LH518iB is in the 18-tonne payload class — running semi-autonomously in a mixed fleet at one of the world’s most demanding underground operations, and it didn’t fall over. Five-hour battery runtime with sub-five-minute swaps is a workable operating model, particularly in automated operations where the machine can position itself for a swap on schedule rather than burning operator time. That’s the quiet advantage nobody headlines: battery-electric pairs naturally with automation, because you don’t need a human sitting in the cab when the energy strategy is swap-based.
The ventilation angle is the real economic story, and this article barely touches it. Diesel underground means massive ventilation infrastructure — fans, ducting, heating in cold climates, and in deep mines like El Teniente, the energy cost of moving air scales brutally with depth. Strip out diesel particulates and NOx and you shrink the ventilation requirement, which is where the actual capex and opex savings live. The battery swap model also cuts heat load. This is why the majors — Codelco included, with El Teniente’s new levels pushing deeper — are serious about BEV regardless of whether the marketing copy about “sustainability” makes your eyes roll. The sustainability narrative is fine for the annual report; the ventilation math is what gets a project approved.
Codelco’s quotes deserve a grin, though. “Transformation of the mining industry of the future.” I’ve heard that phrase attached to autonomous haulage, in-pit crushing, real-time grading, and at least three sensor companies that no longer exist. Translate it: a state-owned copper miner facing declining grades, aging assets, and a massive capital program is looking for any lever that reduces operating cost and improves safety metrics. El Teniente is transitioning to the new Daniel Nouvelandé (Colones) levels, and Codelco needs that transition to work or Chile’s fiscal picture darkens considerably. BEV is a tool in that effort, not a mission statement.
The credit side of this story belongs to the collaboration structure. Both parties ran field data through a joint feedback loop between Codelco’s operations and maintenance teams and Sandvik’s specialists, tracking performance and identifying improvements in real time. That’s how these pilots should run, and it’s why some succeed where others quietly die after the press release. But structure doesn’t guarantee repeatability. Sandvik’s Tommi Valkonen makes the right point — the significance isn’t one result, it’s hitting the full KPI range in a mixed production environment. Mixed fleets are where electric equipment historically struggled, because a battery loader that needs charging infrastructure and a diesel fleet that needs fueling create two maintenance regimes instead of one. If a mine can run both side by side without doubling complexity, the adoption math changes materially.
What to watch going forward: fleet size. One machine proves a concept; twenty prove an operating model. The announcement that Sandvik and Codelco will use these findings to evaluate further BEV adoption at El Teniente and other Codelco operations is the actual news. If the next step is a multi-unit order integrated into a full production level, the thesis advances. If we get another eighteen months of single-unit pilots, that tells you the economics still don’t clear without subsidies or vendor concessions — which, historically, is exactly how these pilots are priced. OEMs routinely eat margin on early fleet placements to buy reference sites. Sandvik wants El Teniente as its showcase because every other miner in Chile, Peru, and beyond is watching. That’s a sales strategy, not charity, and it’s why the “competitive performance” claims should be read with a margin of error.
Risk-focused takeaway for anyone allocating capital here: the direction of travel in underground BEV is now well established, and the equities exposed to it — Sandvik, Epiroc, and the battery and charging ecosystems forming around them — have already priced in a good chunk of the adoption curve. The incremental upside comes from evidence exactly like this trial, but the pullback risk comes from scaling failures nobody writes press releases about: battery degradation in hot, humid, dusty underground conditions over multi-year duty cycles, maintenance cost creep after handover, and charging infrastructure capex at the fleet level. Ten months proves availability. It doesn’t prove battery replacement economics at year four.
El Teniente ran a battery-electric, semi-automated loader alongside its diesel fleet for ten months and the machine did its job. That’s a legitimate milestone, earned the boring way — with data. Just remember the difference between a trial succeeding and a transition being done.
