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

Saturday, June 20, 2009

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

I did the numbers on putting in two Solidnav Voyagers, (or similar
motors) for a total of 16kw at 600 amps draw. I could supply these
motors at half speed indefinitely with power. I have a 7.5kw
generator, and my boat can easily hold a 2kw solar array. With this
setup I would own the worlds slowest cabin curser. ;-) With around
50 hp?, But I would go.

I also did the numbers to kind of come close to replacing the
performance I have and I was looking at two motors each in the 60-80
kw range. Which depending on the motor efficiency would be around 80
hp peak 40 hp or so continuous. To give you an ideal of the amp draw
on the batteries at full throttle assuming 100% efficacy for each prop:
at 48 volts you would need whopping 1250 amps (I have not found a
motor in this range)
at 144 volts 417 amps (These exist)
at 312 volts 192 amp (These exist)
Now times the amps by two (one for each prop) for a total of 160 hp.
Obviously at that amp draw a third of an hour is all you could do with
a $12,000 dollar battery pack, say 800 AH at 48 volt at full
throttle. Now it might be nice to have this speed for 15 minutes but
is it really worth it?

Heck I don't know still on the fence. LOL. Option two at low speeds
is just as amp efficient as option one, plus you have the option to
drain you pack faster if you want, the question is how often would I
want to go faster? I'm guess not very often. The down side to option
two is as stated below It pretty much forces me into a high voltage
battery pack.

But if you had a setup in mind, let me know I would be happy to do
the numbers! That part is fun. Making a choice and living with it is
the hard part. Everything with boats is a trade off....Everything!

Feel free to poke fun at my number above if you find flaws.

On Jun 20, 2009, at 2:52 AM, Hans Kloepfer wrote:

>
>
> James,
>
> Not really sure how much power you are looking for on your boat. You
> have a tall order replacing two big V8's. If you wanted to stay with
> the simplicity of 48v (which would be alot more convenient) have you
> considered belting more that one motor to the same shaft? Would two
> 48v motors per shaft give you the kind of power you are looking for?
>
> --- On Thu, 6/18/09, James Sizemore <james@deny.org> wrote:
>
> From: James Sizemore <james@deny.org>
> Subject: Re: [Electric Boats] Re: Any larger electric boat owners
> out there?
> To: electricboats@yahoogroups.com
> Date: Thursday, June 18, 2009, 2:20 PM
>
> The first hard choice you have to make is the pack voltage, A 48 volt
>
> pack will make buying components for your house solar array easy and
>
> cheap (pretty much standard off-grid setup), and buying a traction
>
> motor big enough to replace your V8 very hard (I only know of one 48
>
> volt high current low voltage motor and the price scarred the paints
>
> of me). If anyone knows of a large high HP 48 volt motor let me
>
> know! (The reason they are rare is that high current draw from the
>
> batteries radically increases the perkert effect, and wire size. )
>
> But if you go lithium or travel on strait solar/generator (You would
>
> need a big array 1600w minimum to get even a few knots. ) 48 volt
>
> would be optimal from a simplicity standpoint.
>
> Or you can go with a 144 volt or 312 volt pack and have lots of
>
> traction motors choices. But very limited inverter charger choices
>
> to supply power to the house.
>
> The DC to DC that I have heard the best gossip on for the high voltage
>
> setup is : http://www.victrone nergy.com/ chargers/ centaur-charger-
> 12v-24v/
>
> 90 DCV - 400 DCV input . You will have to go with a grid-tie
>
> inverter solar cell setup (high voltage solar cells and hight voltage
>
> inverter) They exist but don't have the features of the 48v peers.
>
> I would prefer the low voltage setup myself ( the the lack of motor
>
> choices is devastating) I have a few high voltage setups on paper
>
> but nothing I like enough to pull the trigger on yet.
>
> If you have any question or ideal let me know I have put a lot of
>
> work into different designs, I'm sure I can save you some time looking
>
> for components.
>
> On Jun 16, 2009, at 7:08 PM, mcdonaldmike13 wrote:
>
> >
>
> >
>
> > I just found this site today. I too am interested in converting my
>
> > boat to electric. It is a 47 foot river cruiser with a shallow draft
>
> > with a Volvo v8 sterndrive that I would like to remove. We plan on
>
> > using solar and wind for our house power but am getting lost on all
>
> > the electrical options or non-options. This a go slow boat. Are
>
> > there any viable options out there?
>
> >
>
> > --- In electricboats@ yahoogroups. com, James Sizemore <james@...>
>
> > wrote:
>
> > >
>
> > > 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.
>
> > >
>
> > >
>
> > >
>
> > >
>
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