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    What is my maximum power for this build?

    Ok so I've now made the purchase of a 5000w hub motor with a 80amp controller and a 72v 26 amp battery. What is my maximum power with this setup? If I'm not mistaken you multiply the 72v x the 80amp which gets you close to 6000w correct? What do you think my top speed is with this setup? And now I was wondering, since the 72v battery was the biggest one they had, that's what I got, but what if I want to get an additional battery to get to around 90+ volts can I do that with the controller and motor or will it burn out? If you want more top speed you should increase the volts correct?

    #2
    The Kv of the motor describes how many RPMs you will get for each applied volt. A 72V battery powering a hubmotor with a Kv of 10, would result in a wheel that spins 720 RPMs when it's unloaded (full throttle with rear wheel in the air).

    the second factor affecting the ebikes speed is the outer diameter of the tire. Larger-diameter tires will have a higher top speed, but less hill climbing torque. A smaller wheel is the opposite.

    Comment


      #3
      Also "80 amp controller" that could be 80 amps peak (for 10 sec or so - takeoff etc) but lower continuous amps perhaps? Also depends on what your battery can produce (BMS limits peak/cont. amps)

      From what I understand if you apply full throttle from standstill, you'll get peak amps for takeoff then gradually less amps as you approach top speed.

      Kelly controllers also specify "phase amps" which is different to battery amps
      eg. this one says peak phase 150a, cont. 60a phase amps which is more like 75a battery current peak, 30a battery current continuous. Its confusing and I might be slightly off with the numbers, but its hard to calculate definitively.

      •Peak Phase Current, 10 seconds: 150A.
      •Continuous Phase Current Limit: 60A.



      Good evening guys, I have a doubt that I could never quite understand the difference between the phase current and the battery. For example, I usually set up when the battery 100A, on my lyen , Set the current phase to 260A (2.6 X). Now I have a 200A Kelly (phase), but why if i have max output...

      Does using Johnn in CR's method draw more current from the battery for less acceleration by having a smaller ratio of battery to phase? Or is actual battery current draw related not only to the controller battery current limit but as well as the ratio set? I need a DC current meter... John in...

      Comment


        #4
        Good stuff and I might add that what OP describes sounds like a blast! Checking some of your other posts I see you’re going for mostly street and looking for around 40 MPH? Far from electric bicycle parameters but a potentially exciting mni-moto.

        In order to “guesstimate” potential “top speed” you need to know much more about the RPM/V of the motor(s) along with wheel size and/or final gearing ratios if powering through drivetrain?

        Another thing about system battery power is that 72V is really more like 84V HOC (hot off charger) so when you do Mr Ohm’s calculations, starting fresh from the garage, it’s dissipating something like 6720W. Or, an extra 720W (close to “legal” eBike limit, LOL…” than if calculating using “nominal” pack voltage 72V….

        Not to nit-pick but to educate, folks might also wanna refrain from using A vs. Ah values in these discussions?

        System current flow between a charger or motor/controller is often measured and described using a unit called A or Amperage.

        The “amount” or capacity of current flowing is called Ah or “Amp hour”. In other words, “how much time can the battery deliver an Amperage? We describe battery packs - 52V @ 13.5Ah which is 702Wh. Or, that battery pack can deliver 700W of power for roughly 1 hour of time.

        Have you built other eBikes before? Pics are always welcome and let’s see what you’re going for!

        Comment


          #5
          Originally posted by Electricbiker100 View Post
          Ok so I've now made the purchase of a 5000w hub motor with a 80amp controller and a 72v 26 amp battery. What is my maximum power with this setup? If I'm not mistaken you multiply the 72v x the 80amp which gets you close to 6000w correct? What do you think my top speed is with this setup? And now I was wondering, since the 72v battery was the biggest one they had, that's what I got, but what if I want to get an additional battery to get to around 90+ volts can I do that with the controller and motor or will it burn out? If you want more top speed you should increase the volts correct?
          What kind of battery and motor do you have
          where did you get them
          where is clifton

          Comment


          • Electricbiker100
            Electricbiker100 commented
            Editing a comment
            The battery is a 72v 26 amp battery the notice is rated at 5000w I don't think that is peak power, and I got it through retailers on Amazon, linked to China were it all comes from. Clifton is on New Jersey were I live.

          #6
          Oh wow, a lot more to know than I thought lol thanks though. As of now the whole package hasn't arrived and honestly I didn't do that much of a thorough search on the products I bought as in all the details you guys are mentioning, I just asked around trying to figure out what would be the best combo for the speeds I'm looking to get and the size motor with the battery that I got was what seemed good to get the job done. I'm looking to get 50 + mph on the bike, and I'm not doing a fat bike any more, I switched to the enduro.frame with 19 inch wheels. I'm going to try to find out more so i can tell you guys. I'll definitely post pictures of the build when it all comes in though.

          Comment


            #7
            Originally posted by ykick View Post
            Good stuff and I might add that what OP describes sounds like a blast! Checking some of your other posts I see you’re going for mostly street and looking for around 40 MPH? Far from electric bicycle parameters but a potentially exciting mni-moto.

            In order to “guesstimate” potential “top speed” you need to know much more about the RPM/V of the motor(s) along with wheel size and/or final gearing ratios if powering through drivetrain?

            Another thing about system battery power is that 72V is really more like 84V HOC (hot off charger) so when you do Mr Ohm’s calculations, starting fresh from the garage, it’s dissipating something like 6720W. Or, an extra 720W (close to “legal” eBike limit, LOL…” than if calculating using “nominal” pack voltage 72V….

            Not to nit-pick but to educate, folks might also wanna refrain from using A vs. Ah values in these discussions?

            System current flow between a charger or motor/controller is often measured and described using a unit called A or Amperage.

            The “amount” or capacity of current flowing is called Ah or “Amp hour”. In other words, “how much time can the battery deliver an Amperage? We describe battery packs - 52V @ 13.5Ah which is 702Wh. Or, that battery pack can deliver 700W of power for roughly 1 hour of time.

            Have you built other eBikes before? Pics are always welcome and let’s see what you’re going for!
            Thanks I don't have the parts yet but when it comes in I will definitely make a post for it and give my thoughts on it. Like I said I'm trying to get a 50+mph bike for the streets and I'm not doing a fat bike any more it's going to be on a enduro frame bike, with 19" moto rims. For the motor and controller this link I think is the exact kit. http://m.ebay.com/itm/112321997065

            Comment


              #8
              Originally posted by Electricbiker100 View Post

              Thanks I don't have the parts yet but when it comes in I will definitely make a post for it and give my thoughts on it. Like I said I'm trying to get a 50+mph bike for the streets and I'm not doing a fat bike any more it's going to be on a enduro frame bike, with 19" moto rims. For the motor and controller this link I think is the exact kit. http://m.ebay.com/itm/112321997065
              That looks like a motor with a 50mm magnet--nice. Also, it says 150mm dropouts and it can accomodate a single speed freewheel. So probably a 50mm stator, the largest that they make.

              Comment

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