- This is an interesting thread, and I have been thinking along
these lines myself, though I must admit that I have
reservations. Since I live in a totally solar house powered by
sixty large photovoltaic panels, I have a little experience
with this sort of thing. With a 1000 ampere hour battery bank,
I will share that that is over a ton of battery, and you would
be lucky to have them last a decade. That $4000 worth of
batteries would buy two new 10 horse Hondas, and they would
probably still be going strong a decade later. For starters,
when you start talking about 10 horsepower, you are dealing
with a LOT of electrical power. There is absolutely no
comparison in terms of energy per dollar or energy per pound.
Buy the ten horse honda and relax. On the other hand, IF you
can use the weight as ballast as in a sailboat, the batteries
are able to do double duty. A previous post mentioned using a
submersible well pump. Trace makes a gadget that turns 110 into
220 volts. I have one and will sell it at half price, though in
my opinion this is the wrong way to go. Stay with DC. Smaller
boats can be powered by high thrust commercial units just fine,
and the glen-l idea of putting an electric golf cart motor atop
an old outboard has a lot going for it. The best application
IMHO is a boat that sits a lot in the sun and has a few solar
panels to keep it charged, and possibly a backup battery
charger. By that I mean a 12 or 24 volt heavy duty automotive
alternator (mine was converted to 24 volts by an alternator
shop) powered by a Honda 4 or 5 horse gasoline motor.... or a
smaller generator. Again, this has to tickle your fancy, or it
is not worth doing. Even in a smaller application, you will be
lucky to get by with less than 100 pounds of batteries, and 100
pounds of gasoline will probably take you 10 times as far.
Don't want to hog more space - my bottom line is: think
twice...but maybe do it anyway!
- --- In bolger@y..., Jim Goeckermann <jim@s...> wrote:
> This is an interesting thread, and I have been thinking ...That is why I like the idea of a used diesel powered welding machine,
> ... that is over a ton of battery ...
> ...my opinion this is the wrong way to go.
> ...Stay with DC.
which is 40V 250Amps DC. These units sell at auction used for $3,500
and weigh 1,500 lbs. When you want to move, power up, when not,
power off. The only battery bank would be minimal for cabin uses.
Maybe an electrical engineer could say if the 40V 250Amp power could
be fed into a motor somehow. If the motor could be submerged in
water, then you could avoid a stuffing box, through hull hole, etc..
- A possible problem with this is the duty cycle. The welder was
designed to put out 40 amps on an intermittent basis. Use of a motor
may well exceed the thermal designs of the electronics because power
draw from a motor is constant not intermittent.
You might want to have an engineer look at the internal components
for the intended purpose.
- --- In bolger@y..., "nettech22407" <micwal_va@h...> wrote:
> A possible problem with this is the duty cycle. The welder wasI was concerned about that too, though the Miller Big Blue 251D is
> designed to put out 40 amps on an intermittent basis.
rated @40V DC 250A at 100% duty cycle per their spec sheet. These
welders can be used in fab shops etc. around the clock under constant
Spec sheet PDF file here (takes a while to download):
I agree with you that an electrical engineer needs to design the