Electric Powerboats

Bear Mountain 30 – Sparks

BM30Cruise

I have had a long association with Ted Moores and Joan Barrett at Bear Mountain Boats. We have worked together creating many designs for canoes and kayaks and this project was one that had been brewing in Ted’s mind for some time. With their personal use in mind, it was easy to define what was needed. Fuel efficient, classic, practical and beautiful. Construction is much like his canoes – longitudinal strip planked with fiberglass inside and out.

This project was a true collaborative effort with Ted leading the team and concentrating on the construction process, Jonathan Killing designing, specifying and installing the electrical, solar, diesel, and computer systems and myself designing the hull, deck and cabin.

As described by Ted and Jonathan:

“The Bear Mountain Hybrid 30 is designed for low speed cruising on inland waterways. Up to six passengers can comfortably enjoy day trips with seating in the open aft area. For longer trips an enclosed galley, head, and cabin can accommodate two people.

Eight solar modules charge the battery pack to full capacity between trips. With sunny weather, the pack should recover from 80% charge within 2 days. When underway, a user interface shows the operator the current status of all of the components including power flows and state-of-charge. A simple, intuitive screen allows the operator to see which sources are supplying power and adjust speed to suit the desired balance. For example, for purely solar boating, the operator can match the motor power to the solar input and maintain the battery state-of-charge.”

bm30n1

System Description

“The rooftop Solar Modules provide continuous power to the batteries when the vessel is at rest and helps to offset the load when in motion.

A Diesel Generator engages when the control system detects the need for increased power or when a low battery condition exists. The generator provides the full 3kW load required to drive the boat at top speed with excess power going to charge the batteries.

The Electric Motor provides propulsion through a direct drive shaft to the propeller. Though the motor is rated for 5kW, the maximum theoretical drive power is only 3kW at top speed (including mechanical and electrical losses).

A Battery Pack can be charged by the solar modules, diesel generator, or shore power. Total capacity is 360Ah contained in 16 AGM batteries. Usable capacity is 20% (72Ah), that is, it is best to work in the top 80% of charged state to maintain battery life.

Auxiliary Loads include an inverter to provide 120VAC, bow thruster, and 12V loads such as lights and navigation equipment.”