On Apr 25, 2021, at 10:27 AM, Jeff LaCoursiere <jeff@...> wrote:

? Hi Jay,

We would love to work with you on the battery portion of your design - we have cells and components in stock to make something custom for you if you are interested.? Give me a call!? Number on the website...

Cheers,

Jeff LaCoursiere
s/v Angels Quest

On 4/24/21 9:01 PM, Jay Johnston wrote:

Hello Electric Boats forum!

Any and all thoughts and suggestions are highly appreciated regarding a wooden all-electric boat being built right now. Below are some basic details describing the wooden boat and the proposed electrical components, some of which have already been purchased (motor and motor controller).?

We also have a short youtube video describing where we think the electrical components might reside in the boat, and it also shows the space constraints we are dealing with, we hope this helps explain what we're working on. We haven't build an electric boat before so in a sense we don't know what we don't know. Lots of work still to be done but we wanted to reach out to this group now to get your thoughts.

Electrical components: A 5 minute video showing space constraints and component placement:

Full boat walkthrough: A longer walkthrough video showing progress update of entire boat:

We would like to hear your suggestions and thoughts on the project regarding the electrical system! All comments welcome. We especially would appreciate thoughts on:

Batteries: We don't want to build our own and don't want to manage a BMS (besides programming the hybrid inverter/charger to charge the bank); safety is our top priority, and we think we have a good candidate in the 48V Simpliphi series (more details below). Any thoughts on other off the shelf 48V Lithium solution that might work better for us, considering the space constraints?? We show the bunk where the batteries will go in the shorter video on the electronics here:?

Placement of components: We think we have a rough idea of where the major components and busbars could go; the quick video walkthrough shows some cardboard mock-ups of where things could be placed, but we might not be considering something important.

Solar panels and off-shore charging: Flexible might look better and have some other benefits given the shape of the roof (see the longer youtube walk-through second video at 2:29 ); but rigid panels might hold up better under wind, for example when the boat is being towed down the highway, and last longer in general. Suggestions on panels and wiring? We haven't even begun really investigating the solar side yet, still focusing on the main 48V bus and the shore charging system. Would wind power be worth considering?

Ok, on to the details:?

The boat: Gavia

Description: Gavia is a 25’ all-electric solar motor boat under development. We are now at the stage of investigating the major electrical components with a purchase timeline of 3 months or so (around June 2021).

48V DC System: The motor is a brushed 7.5 kW DC 48V Thoosa Electric Motor. We hope the nominal draw will be around 1-2 kW while under way, but short bursts (1 minute) of 7.5kW are expected (we have not tested the boat in the water yet). Energy will be provided by a 48V lithium-iron battery bank, hopefully with more than 10kWh of usable energy. Solar cells on the roof will be the primary recharge method, hopefully 1kWp or greater, with AC shore power and backup 1kW generator for AC charging. A hybrid inverter/charger should be a convenient way to pack lots of functionality into one box, and AC input/output should be 120V (we are in the USA).

12V DC System: The 12V DC system will be used to run low-wattage house electronics (navigation, radio, windless, house lighting, etc), and 12V bow thruster whose max draw is 1500W. This larger 12V draw necessitates a 12V energy bank (vs relying on DC-DC converter), so a 12V 100A lithium battery will be used and it should recharge from the main 48V system via DC-DC converter charger.

120V AC: 120V AC will be used for a minimum number of appliances onboard, the largest of which is the induction cooktop with a 1800W draw. This will be provided by the hybrid inverter/charger.

We like what we see with Victron and the component integration is appealing. We’ve looked through the sample system designs from Victron and PKYS and our setup probably won’t be too different. Size and weight are major limitations, especially for the 48V battery bank and inverter/charger

Here are some proposed system components so far:

1. 48V Battery: SimpliFi AmpliPhi-3.8-48V wired in parallel (x4 at least)

2. Hybrid Inverter-Charger: Victron MultiPlus-II 48/3000/35-32 120V PMP482305100

3. Charge Monitoring: Victron CerboGX + GX touch 50

4. DC-DC Converter: Victron Solar Charge Controller

5. 12V Battery: Any 12V lithium iron 100Ah+ battery should do fine

6. Solar Panels: Unknown - Flexible Panels to go on the roof

7. Solar Charge Controller: Victron Solar Charge Controller

8. Bus bars, fuses, switches, protection relays, shore plugs, AC bus: Under investigation

Thanks,

Jay

--

	Jeff LaCoursiere STRATUSTALK, INC. / CTO Phone: +1 703.496.4990 x108 Mobile: +1 815.546.6599 Email: jeff@... Website: Address: One Freedom Square 13th Floor Reston, VA 20190
	? ? ?

--
Jeff LaCoursiere
s/v Angels Quest
St Thomas USVI