T-Pain Is On A Boat: Re: [Electric Boats] Any larger electric boat owners out there?

Sunday, May 24, 2009

Re: [Electric Boats] Any larger electric boat owners out there?

Thats an interesting ideal. I might do one motor first and take it out
for a spin and see how hard it is to keep it going in a line with two
different motors! But both gas beasts will go. Not to say I might not
wind up getting one large DC generator if I don't get a reasonable
amount of range. Like you I have never been a speedster I don't want
or need 30 knots.
What I do want is to smell the fresh air when I am out on the boat,
not gas/diesel fumes.

On May 24, 2009, at 6:56 PM, Arby bernt wrote:

>
>
> James,
> I'm currently replacing one of two AQ170 Volvos in my '76 Skipjack.
> I don't hope for a minute that I'll be able to match the fuelish
> motor to the electric, but I do look forward to displacement
> cruising on the electric, with the option of firing up old crusty
> for a trip home on plane. Granted, I'll be changing the 17" pitch
> props for a pair of 12's, so the +30 knots of yesterday won't be
> part of the new plan, but the boat should be able to plane at about
> 17 knots, using the electric to get over the hump. I suggest the
> same for you, if keeping one engine running is manageable. I'm
> considering an High Performance Golfcart AC motor from Thunderstruck-
> EV and a matching controller. I havedesigned and built some 30kW
> motors for other projects, but the prospect of a 300v string of lead-
> acids is a little more than I want to install in the bilge. If you
> really want to go pure electric, don't even consider the replacement
> of the V8's with similar sized
> electrics, but instead use a pair of smaller motors suffient for
> displacement speeds, and stock the cooler using the change.
> Remember, on a boat, and in life, it's the journey, not the
> destimation...
>
> Be Well,
> Arby
>
> ________________________________
> From: aweekdaysailor <aweekdaysailor@yahoo.com>
> To: electricboats@yahoogroups.com
> Sent: Sunday, May 24, 2009 11:16:34 PM
> Subject: Re: [Electric Boats] Any larger electric boat owners out
> there?
>
> Denny is being too nice to say it outright, but what you're looking
> for isn't practical today. You'd be needing nearly 100KW continuous
> power to drive that boat -- a minimum of 12 100AH batteries would
> last about 4 minutes. So multiply by 10 -- 120 batteries to get an
> hour of range (Peukert helps here) at 80% depth of discharge. 120
> batteries is ~7000lbs...300 connections to corrode...740 cells to
> inspect...and one bad cell to ruin your day (or hour anyway).
>
> Steyr has some sweet-looking but undoubtedly pricey hybrid diesels
> that might be worth looking at - that would give you a short period
> of "silent running" before needing to power up.
>
> Otherwise - you can "go green" using biodiesel in conventional
> engines. A 30' sailboat is near the practical limit for pure
> electric due to hull form and battery weight factors - that's why
> they tend to be the focus.
>
> -Keith
>
> --- In electricboats@ yahoogroups. com, "dennis wolfe" <dwolfe@...>
> wrote:
> >
> > James,
> >
> > HP is HP, whatever the prime mover. The continuous (not max or
> peak) power rating of your motor is the number to use.
> >
> > The battery bank is the real power constraint anyway, not the
> motor. You want to consider speed and range. Not much sense setting
> up an E boat that will go fast but drain the batteries flat in 5 or
> 10 minutes. Start the design process by defining the speed and range
> you require, select a possible motor/battery system, evaluate cost,
> weight, performance. Repeat until you are confident you have the
> best compromise.
> >
> > Get Dave Gerr's "Propeller Handbook" to figure the prop size and
> rpm best suited to your boat.
> >
> > Google the "Peukert Effect" to see how rapid discharge affects
> battery capacity.
> >
> > You will be removing around 2500 - 3000 lbs from the boat. You new
> installation needs to maintain the original center of gravity or the
> boat won't float level and if it floats bow down maybe hard to steer.
> >
> > Good luck.
> >
> > Denny Wolfe
> > www.wolfEboats. com
> >
> >
> > ----- Original Message -----
> > From: James Sizemore
> > To: electricboats@ yahoogroups. com
> > Sent: Sunday, May 24, 2009 3:25 AM
> > Subject: [Electric Boats] Any larger electric boat owners out there?
> >
> >
> >
> >
> >
> > I see a lot of traffic on this list for smaller conversions
> replacing
> > A4's and such on 20-30 foot sail boats. Are there any folks that
> have
> > replaced larger motors on cruisers/trawlers?
> > I will be replacing two 427 fords (350hp gas engines) on a 41 foot
> > Chris-Craft. This if for a number of reasons including not wanting
> > the ongoing expense of buying gas, second I really hate the
> monstrous
> > complexity of combustion engines. I have a computer science/
> > electrical background so I am much much more knowledgeable and
> > comfortable with electrical systems. And not to mention the smell
> and
> > noise of combustion engines. The knowledge I lack right now is boat
> > related: prop size pitch ...etc...etc. I don't need the boat to
> plane
> > at 17 knots or anything like that, although if it does all the
> better.
> >
> > My current thinking is to replace the fords with a pair of (Netgain
> > Warp 11'' or Transwarp 11'')'s. The part I can not rap my head
> > around is if I go direct drive with the Transwarp's will they spin
> the
> > props to fast? Or should I keep the transmissions that the fords are
> > bolt to now and go with the Warp's. I would prefer not to have the
> > extra complexity of the transmissions. The Netgains can move a large
> > truck at freeway speeds 70+ MPH. My understanding of the
> conversion of
> > electrical hp to combustion hp is at 144v these motors should be
> about
> > the equivalent of a 150-200 hp gas motors with considerable more
> > torque at the low end.
> >
> > The boat will soon have a fairly large solar array and already has
> > 7.5 KWH generator. So keeping the battery bank feed should not be a
> > problem. I know finding a solar charger/inverter for a 144v battery
> > pack will be a real challenge. Any recommendations are welcome. I
> > would also be very curious of other conversions of larger plaining
> > hull boats, and what motors you use and performance you get now.
> Also
> > any recommendations on motors/charges/ controllers or kits for boats
> > this size would be most welcome.
> >
> > [Non-text portions of this message have been removed]
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
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>
>

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