Why We Build Our Own Batteries

EV batteries have come a long way in recent years. Today it’s possible to buy completed battery packs off the shelf — in fact, that’s what all other electric boat manufacturers do. Purchasing packs is unquestionably the faster and easier way to power electric vehicles.

So why in the world would we choose to build our own batteries?

The simple answer is: it allows us to deliver a much better boat, at a much better price.

The case for customization

Tesla disrupted the auto industry by integrating its custom batteries into the chassis of its cars, rather than retrofitting vehicles designed for gas engines. This created a better-performing car and, among other benefits, gave us the frunk.

By building our own battery packs from the module level up, we’re able to design the packs and the hull at the same time so that the two work together seamlessly. This process — called structural integration — gives us complete control over the battery’s exact size, geometry, position, and performance characteristics. It also allows us to pack in significantly more battery capacity without increasing the weight of the boat. As Robert Binkowski, lead vehicle engineer, explains, “We can design the boat we want, instead of designing around the limitations of someone else’s packs.”

Bigger batteries are crucial for providing enough power for a full day on the water for power-hungry boats — especially ones designed to operate at high speeds or throw a wake. And being able to use your electric boat the same way you’d use your gas boat is what will ultimately drive adoption for watercraft of all sizes.

Investing for the long-term

Having more control over the design and performance of our boats is worth the highly complicated work required. We integrate more than 1,000 parts for each battery and build all of our harnessing in-house. We’ve also gone through an exhaustive process to test our battery packs in all manner of environments. In the long run, this option is also much more cost effective than purchasing off-the-shelf packs. Our material expenses are significantly cheaper than the steep price tags of complete packs, which allows us to offer far more performance for the price.

Data-supported safety

The automotive industry has put immense effort into making battery packs safe. With engineers hailing from electric car manufacturers including Tesla and Rivian, we’ve been able to build off of this foundational work and adapt it to a marine environment.

We employ a battery management system that monitors 20,000 data points a second in each pack to ensure they’re in an optimal state. In the unlikely scenario where it detects an issue with one pack, it can shut that pack off and run on the second.

That’s redundancy you won’t find in other electric cars or boats.

Although building the Arc One’s integrated battery packs took tremendous effort, that hard work will pay off significantly and ripple through development of our future boats. We believe that building a competitive electric boat not only requires this level of customization, but ultimately benefits from the design, weight, and safety advantages it enables.