Well...As a fair comparison I'll go back to the second utility-run
kilo trials 17 years ago. The first was almost entirely trolling
motors and kayaks, but the second brought out the first serious
contenders Those used lead/acid auto battery packs of 72 to 120v, and
the fastest ran 41 mph. One used a motor controller, the other three
used knife switches.
Within two years the record was set at 70.5 mph, again with lead
acid, but at 144v (at 500+ lb) and with knife-switching only because
no reliable high-amp controllers existed. There were high amp
controllers available, but a couple pretty frightening bypass events
made players favor the kamikaze but predictable switch.
In one event the boat was headed out onto the course at no more than
5 mph when the controller went to full power, standing the hull
straight up to pitch out the driver and fall on him. In the second an
owner was in the garage. He'd just finished connecting the racing
outboard type hand-throttle to the pot and was testing the setup.
Without warning or input, the motor spun up until the commutator came
apart. Bits of commutator and end-cap schrapnel were embedded in all
four walls.
Between "don't blink" switching and low power density/ hight weight
batteries going after records was a pretty good challenge. The
switching was less trouble than most would guess, but setting up trap
depth and pack location to lift all the weight free of the water
surface took a lot of testing, and you really needed to know your
power envelope to get most speed with least sag.
The current 98.8 mph record set just 2 years ago was a totally
different deal. The boat was pretty much the same as the 70 mph
record-holder, the motor was identical. At 132v, the Lithium-Ion pack
was at a 12v disadvantage, but at only 80 lb, came out over 400
pounds ahead of the car-pack. And it's extra density combined with
lower weight allowed it to literally fly the boat above the surface
to triple its range and allow the prop to be geared up to design
speed. For the first time ever we saw a return pass faster than the
initial pass (99.7 mph).
In NEDRA, competitors are increasingly turning to light weight
Lithium-Ion packs at really stiff voltage to dramatically improve
already impressive performance. Most here don't need nearly the power
required in drag-racing, so using pack weight as a measure, it should
be possible right now to do some pretty amazing things.
The really big deal to me is that this is just the trickle preceding
the flood. I expect to see the market for electric cars drive battery
development in the same way mandated emission limits went from the
frustrating "Cave-man" combo of PCV and enough hoses on a car to
sustain a rubber plantation to modern, relatively care free, highly
reliable CPU- managed engines. I think we'll see a lot of wonderful
things and think established production will flatten costs
John
On Aug 27, 2010, at 5:55 AM, aaroncostic wrote:
>
> Lead by the explosion of Electric cars in the coming years & the
> advancement of battery technology, do you envision a battery bank
> strong enough to power larger boats in the not to distant future? I
> understand there may be such a thing now, but I am reffering to a
> viable option based on price and weight.
>
> I am planning on building a medium sized houseboat 16' x 60' &
> having it built 14-15 years from now. (Retirement house)
>
> Since none of us are fortune tellers, we will just be speculating.
> But speculating can be useful. . . .
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