Re: [electricboats] Repowering a 1973 Islander Motorsailer with a 10KW Electric Yacht motor

You better get a genset and a hefty battery charger if you plan to motor because that 100 amp hour battery bank is probably only going to get you about 10 or 15 miles on still water at a slow speed and I think that's being optimistic. If you're up against any head wind or sea you won't get half that far. 

If you have a dinghy or small boat with a 10-20 hp outboard it might be easier, quicker, and cheaper to just tie it along side and hip tow the boat the 30 miles and use the electric to assist. And of course you could sail there if the winds are favorable and just use the electric for casting off and docking.  

Just a suggestion.

Capt. Carter

www.shipofimagination.com

On Sunday, November 29, 2020, 03:17:09 PM EST, Ryan Scott Dancey <rsdancey@gmail.com> wrote:

[Edited Message Follows]

About six weeks ago we purchased a 37-foot 1973 Islander Motorsailer from a seller in Seattle. The previous owner had been working towards repowering the boat with an electric motor and had already removed the diesel engine and purchased a 10kw Quiet Torque from Electric Yacht. Since the purchase I've been working towards installing the motor. Our goal is to relocate the boat about 30 miles north from Seattle to Everett where we live and put the boat up on the hard for an extensive refit. To enable that we need to do a minimum amount of work to get the motor installed and powered.

I have built "the Fixture", which is a piece of furniture constructed from marine-grade plywood consisting of a box to hold 4 BattleBorn 100A/12V batteries wired to create a 100A/48V bank, which are wired into a series of breakers, bus bars, a 48V to 12V transformer to power the boat's electrical system, and an MPPT solar power controller for eventual solar recharge. The fixture has been installed into the pilot house and strapped to existing structure. It is wired into the boat's original electrical system using terminal blocks where the old (since removed) house battery bank was located.

We have mounted the electric motor. The compartment it is in originally housed a V transmission, which transferred power from the engine which was mounted below the cockpit facing the bow into the prop shaft which drives a prop located between the keel and the rudder. The previous owner built a wood engine mount structure in situ, which I have covered with fiberglass to seal it against moisture. (This mount will be removed and replaced with a permanent structure in the refit). The motor mounts were attached to the wooden engine mount using the provided lag bolts. The engine is mounted to those bolts. I applied a layer of neoprene under the structure of the engine to provide a bit of motion dampening and to ease the adjustment of the mounting bolts to fine-tune the shaft alignment.

The motor controller will be mounted on the back of the engine but for testing purposes it has not yet been mounted (that will happen this week). The controller is wired to the fixture by 3 meters of 2/0 marine grade cable, even though the Fixture is about a meter from the engine because when we permanently install the battery bank and its associated wiring it will be in the old engine compartment and I didn't want to have to buy another set of engine cables.

The throttle and the display are currently not mounted. This boat has two helm stations, one in the pilot house and one at the stern and we plan to wire both at least temporarily for the trip to Everett.

Yesterday (the 28th) I connected the motor controller and the throttle and display and brought the engine on line for the first time! Tied to the dock, I was able to rev the engine to various RPMs, seeing a battery draw as high as 200A.

The next step, once we have the throttle and display mounted, is to undock, and do donuts on Lake Union near the marina to get a sense of the run time with this battery bank at various speeds and RPMs.

 

https://youtu.be/bLJrR708Oyg