[John Pratt]

Here are links to photos during the rest of construction of my AROHA that I named J. R. Beall:

https://photos.app.goo.gl/xHyqmYbsb7udduhdA

https://photos.app.goo.gl/RgYYYApDCV173M2d9

https://photos.app.goo.gl/kh5VLjRd6QwWWm5E7

https://photos.app.goo.gl/raFYSzHi61MVLj65A

[John Pratt]

My electric propulsion choices:

After talking or emailing with all of the electrical marine propulsion suppliers I could find on the web who would respond, and with a little bit of information about the electrical propulsion system AROHA/WHIO designer Peter Sewell has now installed on WHIO, I have purchased:

1. Motor, including display, controls, etc.:

Electric Yacht QuietTorque™ 20.0 Electric Motor, described here:

https://electricyacht.com/product/quiettorque-20-electric-motor/

This system is actually two 10 kilowatt motors that are both coupled to the same drive shaft.  This configuration makes it possible for this to be a 48 volt system.  For practical reasons, larger motors require higher voltage.

2. Batteries:

I am installing eight Lithium Ion batteries in two banks of four series-connected 12 v batteries:

SOK Marine Grade 12V 206Ah LiFePO4 Battery, Sealed Plastic Box

They weigh 48 pounds each and are described here:

https://www.us.sokbattery.com/product-page/pre-order-marine-grade-12v-206ah-lifepo4-battery-sealed-plastic-box

3.  Other information:

I can squeeze four of the SOK Marine batteries into each of the side benches depicted in the AROHA drawings, so this propulsion system will occupy the same spaces as the diesel motor and fuel tanks specified for AROHA.  I judged battery systems other than lithium to be too large and heavy to be practical.

Watch Youtube videos by Will Prowse for information about LiFePO4 batteries and related matters.

Higher than displacement hull speeds (around 7 knots) are possible because the AROHA hull shape is a semi-planing hull, rather than just a displacement hull.

I chose the Electric Yacht system based on an industry recommendation of the company, my own interactions with the company and my guesstimate that this system will do what I want.

I will report ranges possible at various speeds when I have some experience on the water.  I plan to use the boat for day outings on a large mountain lake, so I expect to be satisfied with relatively small range/running time numbers.

[John Pratt]

Here is a link to photos of my first 10 months of work.

https://photos.app.goo.gl/4PANDNrg2Qbhs5GX6

and through August 20, 2021:

https://photos.app.goo.gl/JrkNrPQuyabkMvnF9

 

[John Pratt]

I do plan to do some posting with pictures, and yes, I plan to use my boat on Lake Chatuge.

John

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