Abtery, the Göteborg, Sweden-based startup developing electric drive systems for projects like the Sarvo Marine 37 electric boat, has been thinking about a smarter way to charge electric boats that better suits the unique needs of marine infrastructure. This week on LinkedIn it is making the case for 350-kW fast charging, with company CEO/CTO Jonas Voss showing off a technology prototype of the solution.

The entrepreneurial Voss is also an Advisory Board Member for Hybrid Greentech ApS and Board Member and CTO for Sarvo Marine. One of his many achievements was taking electric RGNT Motorcycles in Sweden from idea to fully homologated and production-ready motorcycles in less than a year.

The leader of Abtery believes what electric boats need for wider adoption is similar to what electric cars needed when they were introduced—super-fast-charging capability—but delivered in diverse and often remote places on coasts, rivers, and lakes. The solution that his company is working on is battery-based and deployable either as a self-contained onshore unit, included in the construction of a new jetty, or even as a floating jetty where boats dock near existing infrastructure.

All that is needed is a power connection of any type. That could be a standard power connection from a local utility company and it could be supplemented by renewable technologies like solar and wind. The company’s solution uses these inputs to deliver DC charging that’s “significantly faster than a typical ‘supercharger.’”

According to Abtery, a prominent electric boat manufacturer states that its 126-kWh vessel could be charged from 20% to 80% in 1 h via a fast charger or 3 h using a portable charger plugged into three-phase power. The company’s concept “based on technology that exists now” could charge the same vessel from 0% to 100% in around 25 min depending on adequate thermal management being in place on the boat. Smaller capacity vessels—that it expects will make up most electric boat sales in the future—could recharge in less time.

This will be an obvious advantage not only for future electric boat owners but also marinas. First and foremost, it bypasses the infrastructure investment required to upgrade power connections from the grid to install an automotive-style supercharger network. If a site has an electric power feed, the solution can be installed. Being a battery-based system, boats charging on it aren’t drawing on a marina’s shore power, reducing peak-hour demand and reducing the long-term maintenance required on network infrastructure. The battery stacks are modular, allowing the system to be delivered as a standalone unit or elegantly incorporated into new jetty builds.

The smart system’s active cell management maximizes both cell efficiency and longevity. It can be set up to draw power only when necessary, saving the bulk of its recharging for evenings when power is cheapest. And as a cloud-based system, operators can real-time monitoring of the system’s state of charge and use. Recharging can be supplemented by wind or solar installations at the marina.

The battery-management system can detect a poorly performing cell and bypass it without losing any system functionality. With simpler systems, one bad cell can degrade the performance of the entire battery pack.

Abtery believes its solution will be a substantial development in the acceptance of electric boats. The company will set up a prototype in Gothenburg later in 2023 to prove concept capability, improve reliability, and hone the user experience prior to being offered for commercial use.