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Thread: 24volt alternator

  1. #1

    24volt alternator

    Now if you bought a higher voltage alternator, do they draw more power away from the engine to produce? Like if I bought a semi alternator put in my vehicle just for my cell and build a cell for those volts would it be more efficiant......also I have read you can fidget with a car alternator to get higher volts, same question, will it take more power to produce or same power from engine just a more efficient alternator. If that is the case it would lead to a more efficient HHO system right? but thats under the assumption alternator is more efficient...anyways thats my question, does higher volts from alternator require more power from engine, or is it there but only puts out 12 cuz thats what our stuff runs on.

  2. #2
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    It will totally depend on the capability of the alternator. Also, generally, alternators are rated at their top speed. In my job, we often retrofit a large alternator to an engine, for battery charging on a boat. These are often Prestolite/ Leece-Neville ones, rated at 175 Amps at 24V. They are rated for the 175A at 6000rpm, but will do about 150 at 5000rpm as well.
    The power you get out of it will also to a large extent depend on the load you put on it, more specifically the electrical resistance.

    Good luck with it.

    Cheers,
    Martin.

  3. #3
    Sorry if you answered this and I just didnt understand, but does that mean that generally they are all gonna pull the same amount of power per watt? Like a 24v isnt gonna be more efficiant cause it will pull twice the power from car as a 12? Thanks-J

  4. #4
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    Quote Originally Posted by peepoweredcar View Post
    Sorry if you answered this and I just didnt understand, but does that mean that generally they are all gonna pull the same amount of power per watt? Like a 24v isnt gonna be more efficiant cause it will pull twice the power from car as a 12? Thanks-J
    Yes. Watt is the measurement of power and it the product of amps (flow) time volts (pressure). A 30 amp 14 volt alternator will produce a maximum of 420 Watts of power, and a 15 amp 28 volt alternator will produce the same 420 Watts of power. And since the Watts are the same, it will take the same amount of horsepower from the engine to generate the same amount of electrical power (watts) for each alternator.
    1991 Plymouth Acclaim 3L V6.
    1 dry cells with nineteen 6"x8" 316L ss plates, driven by constant current PWM set at 35 amps (13.3V at PWM). 28% KOH electrolyte. Total measured output 2.5 lpm. Mileage went from 18 to 26 mpg, all city driving (44% increase). EFIE set at .370 and I still need to play with ignition timing.

  5. #5
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    PPC,
    Yes- looking at the problem from the standpoint of watts is the way to do it. Say that your electrolyzer pulls 360 watts.. Your 12V alt has to make 30A to provide 360 watts, your 24V alt only has to make 15A to provide 360 watts. As to the load placed on the engine, it is very nearly the same for both alt's because the the overall power out of either alt is the same. I will say though, that the 24V alt may possibly spin a tiny bit easier because higher voltages push (carry?) amperage a little easier than lower voltages. We have a couple of electrical engineers on the board that are being surprisingly quiet about this question.. Probably waiting on other less enlightened souls to stumble through explanations first, so they can swoop in afterwards and make us look foolish..
    [SIGPIC][/SIGPIC]

  6. #6
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    If you go with 24 volts, though, you will need to go with a cell specifically designed to operate at 24 volts. More bipolar plates.
    1991 Plymouth Acclaim 3L V6.
    1 dry cells with nineteen 6"x8" 316L ss plates, driven by constant current PWM set at 35 amps (13.3V at PWM). 28% KOH electrolyte. Total measured output 2.5 lpm. Mileage went from 18 to 26 mpg, all city driving (44% increase). EFIE set at .370 and I still need to play with ignition timing.

  7. #7
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    Quote Originally Posted by peepoweredcar View Post
    Now if you bought a higher voltage alternator, do they draw more power away from the engine to produce? Like if I bought a semi alternator put in my vehicle just for my cell and build a cell for those volts would it be more efficiant......also I have read you can fidget with a car alternator to get higher volts, same question, will it take more power to produce or same power from engine just a more efficient alternator. If that is the case it would lead to a more efficient HHO system right? but thats under the assumption alternator is more efficient...anyways thats my question, does higher volts from alternator require more power from engine, or is it there but only puts out 12 cuz thats what our stuff runs on.
    This is one of the biggest problems getting this to work. 1 HP is roughly equal to 750 watts. The average automotive alternator no matter the voltage will only produce about 350 to 400 watts for every HP it draws from the engine. You are only about 50 to 60% effecient there. Then couple that to the ineffeciency in the cell and the entire system effeciency is well below 50%. There is quite a bit of ground to make up before you even have a chance for improved fuel economy.

    Larry
    2008 Nissan Frontier 4X4 Nismo. 12 MPG baseline with my normal commute and heavy stop and go daily driving. Generator installed and working on 3/29/2009

    Up to 14.5 MPG with no enhancers. Still testing the effects of lots of HHO and no electronic enhancers.

  8. #8
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    A few manufactures of Cells claim there 24 volt Cells have higher MMW than their 12 volt counterpart.

    I don't no how that is, but that's what they say.
    When you're one step ahead of the crowd you're a genius.
    When you're two steps ahead, you're a crackpot."

  9. #9
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    Question

    Quote Originally Posted by H2OPWR View Post
    This is one of the biggest problems getting this to work. 1 HP is roughly equal to 750 watts. The average automotive alternator no matter the voltage will only produce about 350 to 400 watts for every HP it draws from the engine. You are only about 50 to 60% effecient there. Then couple that to the ineffeciency in the cell and the entire system effeciency is well below 50%. There is quite a bit of ground to make up before you even have a chance for improved fuel economy.
    Based from what I have read from this thread, high voltage alternator doesn't pull much energy from the engine? So it is better to buy, average alternators?

  10. #10
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    Quote Originally Posted by frizzyliam View Post
    Based from what I have read from this thread, high voltage alternator doesn't pull much energy from the engine? So it is better to buy, average alternators?
    NO, Watts are watts. They all take the same amount of energy to create.

    Larry
    2008 Nissan Frontier 4X4 Nismo. 12 MPG baseline with my normal commute and heavy stop and go daily driving. Generator installed and working on 3/29/2009

    Up to 14.5 MPG with no enhancers. Still testing the effects of lots of HHO and no electronic enhancers.

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