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  1. #61
    Join Date
    Dec 2007
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    UK, Greece and Spain
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    23,657

    Default Re: Torqeedo Outboards?

    Quote Originally Posted by ghostlymoron View Post
    Is it only me that finds the term 'mothership' a bit pretentious when a applied to a sailing yacht?
    Quote Originally Posted by Bouba View Post
    I deliberately used the term because Im a motorboater and I didnt want any animosity from a mainly sailing forum so I used a gender neutral term it was only to obfuscate not to deceive

  2. #62
    Join Date
    Jun 2001
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    Oban
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    778

    Default Re: Torqeedo Outboards?

    Quote Originally Posted by Alan S View Post
    Energy is measured in Watt hours (Wh)
    Anywhere but here and electricity bills, energy is measured in Joules (or ergs or if you're very old foot.pound-force). There are 3600 Joules in one Watt.hour so perhaps kJ (kiloJoules or MJ would be more convenient.

  3. #63
    Join Date
    Apr 2005
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    Shropshire
    Posts
    8,827

    Default Re: Torqeedo Outboards?

    Isn't a joule something like the energy required to raise the temperature of 1cc by 1C. Very small. You also see kJ on food as a measure of fattening potential.
    Quote Originally Posted by cpedw View Post
    Anywhere but here and electricity bills, energy is measured in Joules (or ergs or if you're very old foot.pound-force). There are 3600 Joules in one Watt.hour so perhaps kJ (kiloJoules or MJ would be more convenient.

  4. #64
    Join Date
    Jun 2016
    Posts
    19

    Default Re: Torqeedo Outboards?

    Quote Originally Posted by grumpy_o_g View Post
    Not really - it's saying that it takes one hour to put 50 watt hours in the battery. You can't put it in any faster but you can take it out a lot faster unfortunately. If you are drawing 200 watts it'll only 15 minutes to empty it (in other words one hours charge will give a certain number of minutes at full throttle but a lot more minutes at half throttle).
    50 Watts also says that it takes an hour to put in 50 Wh.

  5. #65
    Join Date
    Jun 2001
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    Oban
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    778

    Default Re: Torqeedo Outboards?

    Quote Originally Posted by ghostlymoron View Post
    Isn't a joule something like the energy required to raise the temperature of 1cc by 1C. Very small.
    No. A calorie is the energy to raise the temperature of 1 gram of water by 1C. A Calorie or kilocalorie is 1000 of them, widely used in food and nutrition circles.

    Whether it's small or not depends on your perspective/how far away you are .

  6. #66
    Join Date
    Jan 2005
    Location
    South Coast
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    13,827

    Default Re: Torqeedo Outboards?

    Quote Originally Posted by Alan S View Post
    50 Watts also says that it takes an hour to put in 50 Wh.
    No it doesn't. Call it 48W and 12V - that's 4A. If the battery can only accept 12V and 2A then 50Wh will take 2 hours; if the battery can accept 8A then it's 30 minutes. You can't ignore the maximum charge rate which is the limiting factor. The quicker you can shove electrons in (or take them out if you're a classicist) the better but it's slow at the moment. That's the the whole electric car issue.

  7. #67
    Join Date
    Sep 2016
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    SoF
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    9,150

    Default Re: Torqeedo Outboards?

    I think it’s important that you analyze what your actual use of the tender motor is. The problem most people have is either starting or servicing the carburetor of their outboard. That is because of under use. And after the initial use of a new electric outboard I suspect 99% are still underused just sitting in the lazaret. So don’t get bogged down on how long it takes to charge.
    The other point is cost. If I have to predict the future I will say the technology will improve (especially the battery) but the price will always reflect that it’s cutting edge and remain high.
    Neither a Leaver or Remainer be

  8. #68
    Join Date
    Mar 2002
    Location
    Greenwich
    Posts
    7,322

    Default Re: Torqeedo Outboards?

    Quote Originally Posted by grumpy_o_g View Post
    No it doesn't. Call it 48W and 12V - that's 4A. If the battery can only accept 12V and 2A then 50Wh will take 2 hours; if the battery can accept 8A then it's 30 minutes. You can't ignore the maximum charge rate which is the limiting factor. The quicker you can shove electrons in (or take them out if you're a classicist) the better but it's slow at the moment. That's the the whole electric car issue.
    Exactly - in fact it takes about 90 Watts power consumption for an hour to put in 50 Watt hours. That’s wildly inefficient but is a lot quicker inverting and using Torqueedo fast mains charger than simply attaching 12v supply (so says the manual but as I’ve never tried the direct attachment that’s why I asked). In this context saying 50W is silly.

  9. #69
    Join Date
    Jun 2016
    Posts
    19

    Default Re: Torqeedo Outboards?

    Quote Originally Posted by RupertW View Post
    Exactly - in fact it takes about 90 Watts power consumption for an hour to put in 50 Watt hours. That’s wildly inefficient but is a lot quicker inverting and using Torqueedo fast mains charger than simply attaching 12v supply (so says the manual but as I’ve never tried the direct attachment that’s why I asked). In this context saying 50W is silly.
    Irrespective of the efficiency of inverters and chargers, if you put 50 Wh of charge (energy) into the Torqeedo battery in one hour, the rate of charge (power) is 50W even if it takes 90W from the ship's batteries. Just saying 50Wh per hour is a clumsy way of saying 50W.
    Chill.

  10. #70
    Join Date
    Mar 2002
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    Greenwich
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    7,322

    Default Re: Torqeedo Outboards?

    Quote Originally Posted by Alan S View Post
    Irrespective of the efficiency of inverters and chargers, if you put 50 Wh of charge (energy) into the Torqeedo battery in one hour, the rate of charge (power) is 50W even if it takes 90W from the ship's batteries. Just saying 50Wh per hour is a clumsy way of saying 50W.
    Chill.
    I dont think you understand electricity very well - not only is the amount of power coming out of the domestic battery bank different to 50w, so is the amount of power gong into the Lithiium battery. A simple understanding of hysteresis tells you that the power in is never the same as the power out and then you have to take account of the circuitry in the lithium battery to manage the charge cycle. Simply saying watts to explain the increase in charge held over an hour is mistaking a point in time measurement of power consumption at some point in the circuit for a measure of the rate of charge increase.

    Simply resolving the dimensions is unhelpful and means nothing in the context.

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