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Thread: Custom LiPo GPR-S

              
   
   
  1. #11
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    Quote Originally Posted by frodus View Post
    how the heck is that gonna work?
    Haha, which part? There are soo many things that you could be objecting to in just one sentence.
    "We realize that we have not answered all your questions and in most cases, our
    answers have only served to produce more questions for which we have no answers,
    leaving us as confused as before. However, (we believe) we are now confused on a
    much higher level and about much more important things than before."

    1978 Suzuki GS550 - 48V 60Ah Pb-A, Alltrax 4844, Etek-RT
    1997 Suzuki Katana 600 - 18s8p (~72V, 40Ah) 30C Turnigy Lipo, Navitas 500A with D&D Sepex

  2. #12
    Not to be taken seriously DaveAK's Avatar
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    Well I know the Powerpaks can be set up in a master/slave configuration, but the series/parallel stuff is beyond me (at the moment). It's always something I've wanted to try though.

  3. #13
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    Yup, what Dave said. And I am building an assembly to do the series/parallel stuff automatically.
    "We realize that we have not answered all your questions and in most cases, our
    answers have only served to produce more questions for which we have no answers,
    leaving us as confused as before. However, (we believe) we are now confused on a
    much higher level and about much more important things than before."

    1978 Suzuki GS550 - 48V 60Ah Pb-A, Alltrax 4844, Etek-RT
    1997 Suzuki Katana 600 - 18s8p (~72V, 40Ah) 30C Turnigy Lipo, Navitas 500A with D&D Sepex

  4. #14
    Empulse R #24 frodus's Avatar
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    I was speaking about series parallel shifting..... you can't combine the output of each controller.... The FET's require the gate for the FET's to originate at the same point. Just don't get what you mean by using 2 controllers and 2 motors and doing series parallel shift....
    Travis

  5. #15
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    Trav, switchin to PM to avoid thread hijacking.
    "We realize that we have not answered all your questions and in most cases, our
    answers have only served to produce more questions for which we have no answers,
    leaving us as confused as before. However, (we believe) we are now confused on a
    much higher level and about much more important things than before."

    1978 Suzuki GS550 - 48V 60Ah Pb-A, Alltrax 4844, Etek-RT
    1997 Suzuki Katana 600 - 18s8p (~72V, 40Ah) 30C Turnigy Lipo, Navitas 500A with D&D Sepex

  6. #16
    Not to be taken seriously DaveAK's Avatar
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    Quote Originally Posted by Tony Coiro View Post
    Trav, switchin to PM to avoid thread hijacking.
    Why not start a new thread? It's still interesting to some of us.

  7. #17
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    Here are the power and efficiency curves for my D&D motor.
    Attached Images Attached Images

  8. #18
    o_O
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    If I'm reading that correctly, the D&D can take 550A peaks. I imagine that would heat up the motor like mad, though for brief acceleration it may be ok. The lead acids originally in my GPR-S could deliver over 290A and had major kick. Shame that the cells only lasted a few months. Seems that EMS has a habit of setting the controller too aggressively for any of the batteries they use.

    The throttle input on that bike is set to a linear profile -- opening quickly to full throttle immediately draws max current. That made for a responsive albeit twitchy throttle. Throttle settings for lithium cells tend to have a ramp rate where pulling it immediately to full throttle gradually increases current draw (gradual being relative and subjective). This is supposed to protect the cells so they don't get slammed with max current draw immediately. [Someone correct me if I'm wrong about that]

  9. #19
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    I don't know if you are right or wrong about that, but it sure sounds logical to me. That would be like someone kicking you out of bed, instead of letting you smell the coffee brewing in the morning first.

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