T-Pain Is On A Boat: [Electric Boats] Newport 28' Build Plans

Monday, June 22, 2009

[Electric Boats] Newport 28' Build Plans

Hi everyone,

I just wanted to share a few of my thoughts about an electric conversion and
talk about some of the circumstances my local area and sailing habits
require.

I've posted a few times, so some of you may remember that I have a Newport
28' which I hauled an old Atomic-4 out of back in March.

Basically, my boat is used for afternoon sails and for week-to-month long
cruises of the Gulf Islands. I intend to use this rig mostly as a back-up to
help me when winds drop en route and the current is shifting. In my part of
the world, some of the passes will flood at as much as 8kts at their peak,
so you want to be able to scoot through during slack.

This means I see a need for two charging modes -- solar for trickle charging
the house batteries and keeping things topped up while I'm not around, and a
generator to provide outboard equivalence with less noise and fuss. I might
add wind generation at some point just for added capability and to reduce
the time the gennie runs, but I don't really expect anything from prop
regen. There's also a bit of a Fuel Cell posse building up around here (this
is Ballard country, I suppose) and I might consider installing a 2-4kw
hydrogen fuel cell if one ever becomes available at a reasonable price
mostly for the quiet operation and easy fuel transport.

My calculations suggest that the 8kw MARS motor from Thunderstruck would
require about 20hrs of charging per hour of operation at 4kw (about what I
recall was my expected draw to make 4kts.) The Honda 2000i (sadly it looks
like the Honeywell from CostCo won't be up to snuff) would provide about a
2:1 at 4kts. The idea would be that on the occasional "motoring day", there
should be enough capacity to run 8hrs with the generator providing extra
range.

Now from what I've managed to work out it looks like 200Ah @ 36V should
provide decent range at about the same weight as my old Atomic-4. If money
ever starts to grow on trees or if the LiFePO4 batteries come down in price,
I'd look into swapping that out, but you just can't compete with lead-acid
for $/Ah at this point.

That means my overall budget is something like (in CDN):

$2200 - Thunderstruck kit
$1000 - 12v batteries
$800 - 200w solar
$1500 - honda 2000i
$500 - mounting, pulleys, prop

Or about $6000 all told.

Thoughts? One nice thing about this design is I can start with the motor and
add components as time and funds allow.

-pvh

--
Peter van Hardenberg
Victoria, BC, Canada
"Everything was beautiful, and nothing hurt." -- Kurt Vonnegut

[Non-text portions of this message have been removed]