Robert,

Of course you can always put batteries in an optimal location.
But optimization has "some" considerations. Outboard is where
we live so they take up space. Since they are a "huge" power
bank they have to be connected into your power plan. Electric
drives take a lot of current so the farther away the batteries, the
more power losss there will be in the cables plus the cables
themselves are large gage which also adds weight.

If you want to add other "systems" to make best use of this bank
of power then they too should be near the source. Inverters,
generators, distribution panels all find favor being closer to the
batteries. All may be something you add later, but they need
space.

The weight of this bank of batteries does give the designer
flexibility to insure fore-aft balance is mantained. They don't
change weight like water tanks and the sizeable mass can be
moved about some to get the bows level on final install.

Lastly a final "big" consideration is how far can the electric motor
controller be distant from the electric outboards. The motor
controllers handle the current to drives. They should be close to
the motors and not too far from the batteries. Solomon drives
require the motor controller to be not farther than 6 feet. All
controllers are susceptable to noice interference and are best
kept close to the drives. Even your HF radio can wreak havoc on
an electric drive.

I know the "best" weight location is the windward pod. My electric
drive will be close to the LW side and works for me to keep all
those systems in the LW hull. The current Visionnary under
construction in Australia has two drives located near the WW
hull. So with that arrangement if you can spare the space then
the WW hull could be a good choice. I agree drippy is bad but
space on the WW side remains an issue unless we add some.
And you are correct they have to be somewhat central to prevent
hobby-horse.

REgards,

JT


--- In harryproa@..., "Robert"
<cateran1949@y...> wrote:
> -Could the 200 odd kg of batteries and the drive be kept in a
pod ,
> keeping the weight more outboard and the centre of drive more
central
> and keeping the electricity well clear of any dripping masts.-- In
> harryproa@..., "jjtctaylor" <jtaylor412@c...>
wrote:
> > Hi ya Col.........
> >
> > I have known about ETEK for over a year. After doing a bunch
of
> > digging found out they have about half the torque at max
output,
> > as a Solomon ST-37. Yes they are going to heat up a bunch
> > trying to overprop an ETEK. In addition they run at 3600 rpm
and
> > have to be geared down to something useable. They are
rated
> > at 6HP but only at max rpm, the torque ramps like a fuel
powered
> > engine so they lack grunt power a low speed.
> >
> > The big weight is not the engine (motor) but the batteries.
The
> > motors are not more efficient so watts consumed is the
same as
> > supplied by the batteries, no matter whose motor it is. Want
to
> > drive a Visionarry boat at 10 knots, it will take about 3-4KW
per
> > hour. Battery banks have to be at least double that size
cause
> > current released drops significantly after 50% capacity is
spent,
> > plus it isn't good for the batteries. So you will need at least
> 6KW
> > in batteries, just to run an hour. A 60lb battery supplies about
> > 1KW. You will need not less than 6 to run an hour.
> >
> > Doesn't matter 48V, 60V or 144V, you still need that kind of
> > capacity to drive the boat. I would not have anything less
cause
> > you never know when going fast is needed.
> >
> > Not sure ETEK is sufficiently marinized. Need to know if it
will
> > run if soaked (immersed) in salt water. Overheat is a real
issue
> > so not sure how the ventilation is handled.
> >
> > Granted the motor is cheaper, but life is full of choices and
> risks.
> > Have not seen the ETEK commercially used anywhere
except
> > lake outboards. I wouldn't give up on 'em but wait till Myles
has
> > the issues resolved and you are prepared to accept the
battery
> > mass required. Lots of folks complain bitterly about anemic
> > outboards, don't want to have anemic electric outboards.
Happy
> > peppy boating sure beats a drifter.
> >
> > Regards,
> >
> > JT
> > > >
> > > Hi John,
> > >
> > > Have you considered a couple of Etek motors instead of
the
> > Solomon
> > > solution?
> > > The advantages as I see them are:
> > >
> > > -Less weight
> > >
> > > -Similar power (if a cooling cowl with fan is employed)-
> > > see Myles Twete's site,mentioned at-
> > >
http://groups.yahoo.com/group/electricboats/message/2478
> > >
> > > -Better manoeverability - able to "turn on a dime"
> > >
> > > -Less cost (much less) - a spare motor could even be
included
> > >
> > > You could still drive 16" propellors if you used a 4:1
gearbox,
> or
> > > equivalent pulleys.
> > >
> > > Regards,
> > >
> > > Col Campey