A crazy idea?

Discussion in 'Hybrid' started by claydog, Jul 20, 2011.

  1. claydog
    Joined: Dec 2010
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    Location: michigan

    claydog Junior Member

    I've been kicking around an idea for a while for a hybrid drive for use in a light weight planing Cat. The Cat I have in mind is only intended to be better looking,with a bit better rough water performance, than a typical pontoon boat. The drive system I've been thinking about uses a snowmobile 2 stroke motor and drive system for primary propulsion and an electric motor connected to the jack shaft via belt that can operate as a secondary “quite” drive while fishing or cocktail cruising. If my understanding of electric motors is correct the E motor can also work as a generator while under power of the gas engine to help keep the batteries topped off when away from the dock. This is just a little more than a napkin sketch and there's a lot of true engineering that's way over my head that I'd have to hire out if I was to go any were with this. The amount of knowledge freely shared on this site is incredible and I'd really like to hear opinions of what I've been thinking

    xx517-7.jpg

    hybred1b.JPG
     
  2. Stumble
    Joined: Oct 2008
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    Location: New Orleans

    Stumble Senior Member

    There are dozens of threads covering this on the board, but the short answer is that the energy density of batteries is about 1/50th that of diesel or gas. It is possible (though very very expensive) to do something like this, but it really isn't practical given the huge installation of batteries.

    If you really want to do something like this, then installing a trolling motor is about the best option.
     
  3. daiquiri
    Joined: May 2004
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    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    Claydog, your're pretty good with that 3D drafting software. :)
    I think this idea is viable, though it will be costly. You should hear Jeremy Harris for details about battery and e-motor sizing, electrical wiring and about charge regulators necessary for the battery-charging phase. He is in the electric-boating world. :)
    Stumble, I understand that the electric drive will be used for trolling and low-speed ops, which is ok. Going at planing speeds with batteries only is, of course, out of question.
    Cheers
     
  4. kerrett
    Joined: Jul 2011
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    Location: italy

    kerrett Junior Member

    Hi daiquiri, I wrote you via mail... Sorry to disturb you.. :)
     
  5. whitepointer23

    whitepointer23 Previous Member

    looks like a good idea, i don't see why it has to be expensive, motors are available cheap and a couple of n200 cat batteries would power it for quite a long time and when it slows you just run home on the petrol motor. i met a bloke who ran a trolling motor on his 12 ft tinny and he gets 4 hours out of an n70 landcruiser battery. i can understand going the hitech expensive route for a fancy electric vessel but its not like you are relying on batteries to get home.
     
  6. daiquiri
    Joined: May 2004
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    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    Ciao Kerrett,
    ho visto il messaggio ma non ho avuto tempo per rispondere. Se non ti dispiace, lo farò oggi pomeriggio, con più calma.
    A presto
     
  7. kerrett
    Joined: Jul 2011
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    Location: italy

    kerrett Junior Member

    Grazie mille, nessuna fretta, era solo per sapere se ti era arrivato..
    A presto
     
  8. claydog
    Joined: Dec 2010
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    Location: michigan

    claydog Junior Member



    Stumble,
    Thanks for the comment and I hear what you’re saying, a trolling motor certainly is the easiest and most cost effective way of running a boat on an electric motor. I work in the automotive design business and have been involved in enough concept builds, that building a custom car for myself just for fun has lost its appeal to me so I’m looking into building a custom boat. Mostly I’m in the very early stages of the design spiral and exploring a few different ideas that combine the key attributes of the 2 different boats I need to cover the way I use boats if I just went out and bought something off the shelf. Being an avid snowmobiler and having built a custom electric golf cart for a customer in the past, this idea been kicking around in my head for a while. I’m hoping a few of the electric boat gurus will chime in to help me figure out if my expectations of performance are in the ball park of reality.


    Regards Andy
     
  9. claydog
    Joined: Dec 2010
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    Location: michigan

    claydog Junior Member

    Thanks Daiquiri, I think I do OK, but I work with too many people that are really good to consider myself anything but OK. I’m hoping Jeremy will take an interest and can give me a bit of E-boat for dummies advice.

    Regards Andy
     
  10. whitepointer23

    whitepointer23 Previous Member

    thats what i would have said.
     
  11. jesdreamer
    Joined: Jan 2013
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    Location: Alabama

    jesdreamer Junior Member

    I am trying to find an appropriate forum for my idea/question -- tried the Briggs & Stratton thread under outboards w/o much response -- Perhaps someone here can help.
    I want a small electric start outboard but find nothing in the 4-5-6HP range. I would like to remove the recoil drive and shroud from a Briggs 5HP air cooled outboard (everybodies favorite outboard) and add a belt drive to combo starter/generator from a gas engine golf cart. Would use a batery to start and recharge during use -- Any thoughts on the subject??
     
  12. El_Guero

    El_Guero Previous Member

    There is a tadpole trike company that does some similar designs.

    They are not that expensive.
     
  13. DCockey
    Joined: Oct 2009
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    Location: Midcoast Maine

    DCockey Senior Member

    You will generally get a better response to a question by starting a new thread rather then asking the question in a thread which is only slightly related to your question. To start a new thread pick a forom/subforum such as Propulsion - Hybrid and then click on the "new thread" button on the left side above the list of current threads.
     
  14. masalai
    Joined: Oct 2007
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    Location: cruising, Australia

    masalai masalai

    The underwater section of the hulls is indeterminate so efficiency there is an unknown.

    The drawing-lines suggest that the propellers may be slightly downward tilted at the stern? (WHY)?
    Where is the thrust bearing (WHY, where is it? - remember that is what takes all the force of pushing the boat under power.)
    There is also a suggestion that the drive shaft is fitted with a CV joint (WHY?)
    Why electric drive? (converting to make electricity and reconverting to drive and the weight penalty and complexity for no real advantage?)
    20% loss in conversion to electricity ? (most generators are rated at .8 and the same applies to motors - OR WORSE)
    20% loss in driving the electric motor from the battery?
    energy loss in storage?
    cabling loss (charger to battery to motor) the battery? At a guess some 10mm in diameter fine strand TINNED to carry slow load...
    and all that extra battery weight in a catamaran hull (WHY this bane of performance in a cat?)
    Belt drive gear box system (WHY?)
    reverse gear (WHERE? / HOW?)
    WHY? the big slow revving propellers? - those 4000 to 6000rpm engines will not handle those wheels at 1:1 :?:
    The aft sections of the hull suggest a cavitation problem for the propellers. http://www.boatdesign.net/gallery/showphoto.php/photo/9660/ppuser/22903 may give a solution - that C10 does 15 knots cruise.

    Run a pair of diesel nanni/kubota saildrives 20hp a side and those big wheels may give you more than 10knots and a 3 litre/hour fuel burn MAX at 3000rpm


    At cruise my 40 ft x 21.4 ft cat gives 2 miles per litre at 2500rpm... 'CNO' weighs up to 6500kg ready for extended cruise... 'CNO' has a range of 2000 nautical miles at 7+ knots on 1200 litres of fuel both engines running... I drove 910 nautical miles from Brisbane to Cairns visiting and exploring lots of islands and used some 450litres of diesel...
    http://www.boatdesign.net/forums/boat-building/my-little-piece-peace-25962-138.html#post606997 and http://www.boatdesign.net/forums/boat-building/my-little-piece-peace-25962-138.html#post607395 for the most recent images of my boat...
     

  15. nickolastd21
    Joined: Apr 2013
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    Location: Plymouth UK

    nickolastd21 Junior Member

    hi just thought I would share my electronic propulsion results.

    I have a gk24 yacht witch originally came with a 6hp lister diesel, I have since removed it and replaced it with a direct drive from a lg washing machine and re wound the coils for better match on my controller which is a standard 200A 3 phase brushless controller for rc helicopters.
    total peek power input is 4.8kw so can drain through batteries at a rate but i don't need my prop to cavatate, so at about 50% power I can drive my boat along happily with the stock 2 blade prop.
    a suitcase gen-set in an aft locker is adequate backup to drive it without the batteries in the loop.
    i only ever require my motor for moorings and birthing so runtime from 4 x 12v 110ah deep cycle batteries (24v in parallelx2)
    its all dc so i have a 2farad capacitor array to soften the impact on the batteries from the controller.

    any way hope its of any use, i can upload photos soon as my new camera arives
     
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