Electric Wave runner Help

Discussion in 'Jet Drives' started by rotzinger, Nov 29, 2010.

  1. rotzinger
    Joined: Nov 2010
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    Location: mexico

    rotzinger Junior Member

    Hello fellow boaters

    Look my project is to make an electric wave runner WITHOUT sacrificing performance, I’ve already resolved the electricity problem, and my problem now is to know what size of electric motor I need to make the wave perform the same as the gas one. This is a normal Yamaha 600, I just want it to be the same as the gas one or close.

    Thanks for your help guys
     
  2. marshmat
    Joined: Apr 2005
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    Location: Ontario

    marshmat Senior Member

    Hi rotzinger,
    Such conversions have been discussed on here before. For example:
    http://www.boatdesign.net/forums/propulsion/electric-jet-ski-conversion-7302.html
    http://www.boatdesign.net/forums/boat-design/electric-waverunner-27393.html
    To summarize: A few people have built electric PWCs with comparable top speed to the gas version, but the endurance/range is very limited. Read the linked threads in detail.
    It's impossible to make a reasonable suggestion regarding the motor without also knowing what the power source (batteries) will be, the intended weight of the system, and the design priorities (do you want range, top speed or acceleration / low-speed fun?)
     
  3. rotzinger
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    rotzinger Junior Member

    The power source I am thinking of is 10 kg =) and it will, in theory, give me 1 h 30 min in a 6 kw motor at top speed. The thing is I need to know the motor size to calculate the power output I need.
     
  4. marshmat
    Joined: Apr 2005
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    marshmat Senior Member

    1h30 @ 6 kW = 9 kW.h = 32.4 MJ, excluding losses. Better than 3.2 MJ/kg energy density.... are you fiddling around with lithium-air or nanowire batteries, rotzinger?

    If you want to match the gas powered PWC's top speed, the power-to-weight ratio of the electric boat should be similar to the gas one. 6 kW = 8 hp, you'd need at least four times that (possibly a fair bit more) to get a comparable power to weight ratio. 6 kW might be enough to get it to plow around at 10 mph with its bow in the air. You might be able to find a forklift motor from which you can coax 24 kW / 32 hp, which would be enough to get the PWC moving reasonably well.

    If you care more about how it accelerates and how it performs at lower speeds, you can probably get by with a lower rated motor. Anything I suggest, though, would be a wild guess without a lot more information about the boat and the already-determined aspects of the proposed conversion- especially the mystery power source. (If the numbers you provided above are real, I suggest you give one of the big carmakers a call. Show them the working prototype and you should have ten million dollars in your pocket by the time you leave the office!)
     
  5. rotzinger
    Joined: Nov 2010
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    rotzinger Junior Member

    no man its not a battery source jajajaja its waay better....... hydrogen fule cell muajajajajajaja at long last you know the truth jajajajaja its all in theory and it might not even be cost worthy to get such a big fule cell. my problem is to find the correct motor an then try to get the correct fule cell. the numbers i have are from a fuel cell airplane =)
     
  6. rotzinger
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    rotzinger Junior Member

    soo you think i would need 35 hp to run like gas???? i have little experience in marine stuf. my hull is an old yamaha 700 or something like that
     
  7. marshmat
    Joined: Apr 2005
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    Location: Ontario

    marshmat Senior Member

    Ahh, OK then.
    A one-off 24 kW mobile fuel cell using current technology is roughly $75,000 USD. There's a good chance that could be brought down to $7500 or so if/when carmakers start mass producing them.
    For the moment, if you want to pour $75k into rebuilding a PWC, that's your decision. It would not be mine.
     
  8. rotzinger
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    rotzinger Junior Member

    yhea thats the point jajajaja i heard you can make the cells at home i might give it a try jajajajaja
     
  9. daiquiri
    Joined: May 2004
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    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    What does "jajajajaja" mean?
     
  10. mark775

    mark775 Guest

    Almost the same as "Gadagadagadagada", which would signify a joke. It's a Mexican thing (or maybe Latin American? - I know a Venezuelan that does it too). Why wife used to do it too to signify laughing in type. It seems nervous to me.
    Hombre, are you on Tequesquitengo? You'll make a fortune in rentals if you can pull it off without electrocuting yourself! Where will you get the hydrogen?
     
  11. rotzinger
    Joined: Nov 2010
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    Location: mexico

    rotzinger Junior Member

    well my friend it just happens to be that ive lived all my life in mexico so i kind a use latin expresions and it also happens to be that im a Praxair dealer so y can get hydrogen realy easely. and no, im not in tequesquitengo, im in cancun.
     

  12. CatBuilder

    CatBuilder Previous Member

    I see people from South/Central American who have Spanish as a primary language use it in place of "Ha ha ha ha"

    It signifies laughter, but it's not English. It's Spanish (of American origin, I think).

    Note that in Spanish, the word Jalepeno is actually pronounced "hallapeenio" The J's take on a H sound, so you can see the connection to "ha ha ha ha"
     
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