Times up for Petrol cars.Where does that leave Boats

[PADDLES]

chris, 64kW is 64000W.

watts = volts x amps. 64000 divided by say 72V gives about 890A. this amount of current will pretty much turn most cable to a puddle in a jiffy.

looking at the continuous rating of 12.8kW @72V you're still going to draw 177A so the motor cables will need to be around 70sq.mm. for say 5 hours running you'll need at least 1500A/hrs of capacity so you only discharge the batteries to a bit under 50% in a full cycle. to get your 72V however you'll need 6 x 12V batteries in series plus start paralleling them to give you the capacity.

noel, you're right, the energy has to come from somewhere. i think it was isaac newton who came up with the theory that energy cannot be created or destroyed. the thing is that a power station can create electricity (or energy in a usable form) in a much more efficient manner and that's why it's better to use power from a station rather than our own generator. it's sort of like the whole 2s vs 4s debate on a much bigger scale.

[choppa]

when i was wasting money by making heaps of phone calls and doing searches everywhere for something to bolt onto the tinny other than the 15hp johnno thats ""still"" there,,, i found a few interesting sites from old and new days

bio diesel inboards are commonplace o/s,,,,, as is gas conversion,,,,albeit marketing keeps the interest low as does manufacturers buying patents etc to ""safeguard"" their own interests

anyone remember the bloke who made the headlines here in qld on a ""water powered"" engine,,,, first thing that comes to mind is steam,,, but he had something (so reported at the time) extra to give less emission problems and sustain HP,,,, it lasted about a month and then he was bought,,,, now deadly silence issues are in place

someone mentioned above to look at science fiction,,,, not a silly comment at all,,
it was only 50 years ago and most of the population laughed at the concept of a man landing on the moon,,,,

and for all you young scientists out there,,,, try a little experiment,, you need a:

paper cup,,,,,, not plastic and it can be waxed like the disposable coffee cups

water,,,,,,,,,,,, fresh or salt,,,,, doesn't matter

open flame,,,,,,,,, camp fire is great

place water in cup and fill to about 6mm from top,,,, hold over heat with tongs,, but don't allow flames to ""run"" up the side of cup,,

watch what happens

julius somner miller,,, 1969,,,, just before the infamous egg in a bottle experiment,,,,,,,,,,,,,,,,,,,,,,,,,,,lol

choppa