For its customer Pure Watercraft, Californian company Motivo designed, developed, and tested a high performance 700V, 210 kW continuous pure electric drivetrain with a 70+kWh battery pack.
The boat can reach speeds in excess of 45mph, has a 1.5 hour range at 25mph, and can be recharged in less than 5 hours. Pure Watercraft’s vision was to create a high performance electric boat that offers lower emissions, higher efficiency, and an overall better boating experience without compromising performance. Pure Watercraft needed a robust and reliable prototype to demonstrate that an electric boat could match the performance of a V8 powered competitor.
“So, the main challenge of this project was to create a reliable high efficiency electric boat, a task that other companies have attempted but not succeeded in. The boat needed to be high power and high performance, and be recharged easily in an afternoon. The battery system, drive train, and cooling system needed to be packaged efficiently and cleverly to fit below deck in the tight confines of an existing boat hull yet still deliver the necessary power. Furthermore, the weight distribution of the boat needed to stay the same as its previous gas-powered counterpart”, explained Motivo, that cleverly designed a custom gearbox that placed the 700V motor outside the hull, submerged in the salt water, in order to maximize space in the hull for other components.
To achieve a good seal, Motivo designed a custom rubber gland to pass the three motor phase leads, oil lines, and control line through the hull. The custom powertrain control module, modular water cooled lithium-ion marine battery packs, chargers and inverter were designed to fit tightly below the deck of an existing hull. Cooling systems for the batteries and power electronics cooling are carefully routed to integrate inside the hull. The drivetrain was also designed to work across a wide range of boats.
