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Thread: How much LifePO4 battery and What would be the range for AC-23

              
   
   
  1. #21
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    Quote Originally Posted by milton View Post
    I am in US. So the average highway speed would be about 60 mph thats 96kph. I assume at that speed the motor would be rotating at about 3000 RPM with direct drive!! (Hugues, you would know better since you already have a motorcycle with about the same motor in there).

    The website says the following about the battery and I am not sure if the 7.5 kw/kg is correct either. Thats a lot of energy per kg. If that is correct then I would get 82 kW with 16 batteries (11 kgs):
    Advantages over traditional Lipoly batteries;
    • Power density reaches 7.5 kw/kg.
    • Less Voltage sag during high rate discharge, giving more power under load.
    • Internal impedance can reach as low as 1.2mO compared to that of 3mO of a standard Lipoly.
    • Greater thermal control, pack usually doesn’t exceed 60degC
    • Swelling during heavy load doesn’t exceed 5%, compared to 15% of a normal Lipoly.
    • Higher capacity during heavy discharge. More than 90% at 100% C rate.
    • Fast charge capable, up to 15C on some batteries.
    • Longer Cycle Life, almost double that of standard lipoly technology.
    Something isn't adding up.

    The link claims a 7500mAh capacity, at a voltage of 7.4V.

    Making the conversion, that's 7.5Ah @ 7.4V. Ah x V = Watt hours, so 7.5 x 7.4 = 55.5 Wh.

    55.5/350g= .16 Wh/g, roughly.

    .16Wh/g x 1000g = 1600Wh/kg

    1600Wh/kg / 1000Wh/kWh = 1.6 kWh/kg

    1.6!=7.5

    HOWEVER, I notice their "7.5kW/kg" figure doesn't include the "h" there... so they are probably talking instantaneous power (max discharge rate x output voltage), which is definitely NOT a measure of capacity and won't be useful in determining your effective range.

    Sent from the Future via Google Skynet

  2. #22
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    Was out on vacation (bachelor party) in Vegas, my first time and much needed break. when i can beck i got a treat in my mail..IMG_20160218_020617.jpg its freakin heavy.. but i am excited. Now need to get the rest of the parts together. I will have to go through Huges instructions to get all the parts together.

  3. #23
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    Huges.. Can you let me know what brand did you use for the contactor, pre-charge relay (they send me a key switch relay, do i still need to use a pre-charge relay?) and DC to DC converter?

  4. #24
    Senior Member Hugues's Avatar
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    Quote Originally Posted by milton View Post
    Huges.. Can you let me know what brand did you use for the contactor, pre-charge relay (they send me a key switch relay, do i still need to use a pre-charge relay?) and DC to DC converter?
    I believe i bought this guy:
    http://www.electricmotorsport.com/ev...200a-cont.html


    The Curtis controller does not need a pre-charge system, it does it on its own.

    DC to DC converter: yes i do have one. You could manage without and take your 12-14 v from the 2 first LEAF packs, but then they would get discharged faster than the rest of the pack. Or have a separate battery for 12 volts..I personally think the DC-DC converter is less complicated.
    Regards from Switzerland
    My 2.5 Upgrade Thread

  5. #25
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    Quote Originally Posted by milton View Post
    Huges.. Can you let me know what brand did you use for the contactor, pre-charge relay (they send me a key switch relay, do i still need to use a pre-charge relay?) and DC to DC converter?
    I use a Vicor VI-24P-EV DC to DC because it has a pull down enable that floats around 13V so it can work through the stock key on your bike without putting out of range voltages on it. It also can come with a BUSMOD piece which gets you to screw terminals instead of just solder pins. You may want the 2TP model for 110V nominal because you have a higher pack V than I have.

  6. #26
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    Thanks Skahle.. I'll check it out

  7. #27
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    milton could you do a close-up of the motor name plate so the info on it is readable?
    Last edited by Electro Flyers; 19 February 2016 at 0915.

  8. #28
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    Here's the picture attached

    IMG_20160221_010124.jpg

  9. #29
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    Skahle / Hugues, What BMS have you guys used for your battery? I am getting a 24 module 96v 124Ah battery. Trying to figure out what BMS to use. Its going to be a 2x 12 Module pack.

  10. #30
    Senior Member Hugues's Avatar
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    Quote Originally Posted by milton View Post
    Skahle / Hugues, What BMS have you guys used for your battery? I am getting a 24 module 96v 124Ah battery. Trying to figure out what BMS to use. Its going to be a 2x 12 Module pack.
    Orion BMS, the version good for 36 cells
    Regards from Switzerland
    My 2.5 Upgrade Thread

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