Why Is Subaru Using Solid-State Batteries in Robots Instead of Cars?
If you’ve been following the electric vehicle (EV) world, you’ve probably heard the buzz about solid-state batteries. They’re often called the holy grail for EVs—promising higher energy density, faster charging, and better safety than today’s lithium-ion packs. So, it might surprise you to learn that Subaru, a brand known for its rugged cars and outdoorsy image, is already using solid-state batteries. But not in their cars. Instead, they’ve quietly rolled them out in the robots that build their engines and transmissions.
What’s going on here? Why would Subaru leapfrog the automotive application and start with factory robots? The answer is a mix of practicality, innovation, and a dash of clever risk management.
What Makes Maxell’s Solid-State Batteries Different?
Let’s break down what Subaru is actually using. The batteries come from Maxell Ltd, a Japanese electronics company with a long history in industrial tech. Unlike traditional lithium-ion cells, which use a liquid electrolyte, these solid-state batteries rely on a ceramic-like solid electrolyte. That’s a big deal for a couple of reasons.
First, solid electrolytes are less prone to overheating and catching fire—a key safety advantage. Second, they allow for higher energy density, meaning you can pack more power into a smaller space. And third, they can handle faster charging without degrading as quickly. In theory, this makes them perfect for EVs.
But here’s the catch: Maxell’s current solid-state batteries are tiny—less than 1 kWh in capacity. That’s nowhere near enough for a car, which typically needs 60-100 kWh or more. For now, these batteries are best suited to smaller, less power-hungry applications.
Why Start With Factory Robots?
Here’s where Subaru’s strategy gets interesting. The robots in their Oizumi engine and transmission plant (north of Tokyo) have always needed backup batteries. These aren’t powering the robots’ main functions, but they’re crucial for things like memory backup and emergency shutdowns. Until now, Subaru had to swap out these batteries every one or two years—a tedious and wasteful process.
Enter Maxell’s solid-state cells. Thanks to their chemistry, these batteries can last up to 10 years before needing replacement. That’s a game-changer for factory operations. Fewer battery swaps mean less downtime, less industrial waste, and lower maintenance costs. Subaru’s own statement highlights this: by switching to all-solid-state batteries, they’re reducing both waste and maintenance work.
It’s a classic example of a company using cutting-edge tech to solve a real-world problem—just not the one everyone expected.
Is This a Stepping Stone to Solid-State EVs?
Naturally, the big question is whether Subaru’s robot experiment is a preview of what’s coming for their cars. The short answer: not yet, but it’s a crucial first step.
Solid-state batteries are notoriously tricky to scale up. Making a tiny, reliable cell for a robot is one thing; building a massive, affordable pack for a car is a whole different beast. Issues like manufacturing complexity, cost, and durability under automotive stresses still need to be ironed out. Subaru’s move lets them gain hands-on experience with solid-state tech in a low-risk environment. If something goes wrong in a factory robot, it’s a lot less catastrophic than a battery failure on the road.
This approach mirrors what other Japanese automakers are doing. Toyota and Nissan have both announced plans to launch EVs with solid-state batteries in the next few years, but they’re also starting small—sometimes with hybrids or niche applications before going all-in on mainstream EVs.
How Does This Fit Into Subaru’s EV Strategy?
Subaru’s relationship with electrification has been, well, complicated. Just a few months ago, the company publicly admitted it was re-evaluating its EV strategy, citing concerns about slowing EV sales in some markets. Yet, almost in the same breath, they launched their second all-electric model for North America, the Uncharted—a rugged, dual-motor crossover with 338 horsepower and a 0-60 mph time of 5 seconds.
So, what gives? Subaru is clearly hedging its bets. By investing in solid-state tech for industrial use, they’re building expertise and supplier relationships without betting the farm on a single, unproven technology. When the time is right—and when solid-state batteries are ready for prime time in cars—Subaru will be better positioned to make the leap.
What’s the Real-World Impact for Subaru and the Industry?
Don’t underestimate the ripple effects of this move. By extending the life of robot batteries from 1-2 years to a full decade, Subaru is slashing maintenance costs and industrial waste. Multiply that across dozens or hundreds of robots, and the savings add up fast—not just in dollars, but in environmental impact.
It’s also a subtle but important signal to suppliers and competitors: Subaru is serious about next-gen battery tech, even if they’re not first to market with a solid-state EV. As the automotive world waits for the solid-state revolution, these incremental steps matter.
The big takeaway? Innovation isn’t about perfection—it’s about smarter adjustments. Start with one change this week, and you’ll likely spot the difference by month’s end. Subaru’s robot batteries might seem like a small step, but they’re paving the way for bigger leaps in the future—both on the factory floor and, eventually, on the open road.