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Thread: C rating???

  1. #1
    RC Competitor
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    C rating???

    Hello everybody!

    Recently i made a thread about esc failure. luckily it was still under warranty and I sent it back to traxxas, and they are sending out a new one!

    once it arrives I would like to run the car in 2s parallel. I have a venom 2s 35c battery right now and it works great. I have heard that higher c rating is better, but the other day I looked at the specs of the motor and esc and it says it can only go up to 50a. C rating I believe stands for continuous amps. So if doubled it, it would be 70c and I could be looking at another fried esc and maybe no warranty which would really stink. Please tell me if I am correct in assuming that higher than 50c would blow the system out.

    Thanks!

  2. #2
    RC Racer
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    Quote Originally Posted by MiniSummit50Mph View Post
    Hello everybody!

    Recently i made a thread about esc failure. luckily it was still under warranty and I sent it back to traxxas, and they are sending out a new one!

    once it arrives I would like to run the car in 2s parallel. I have a venom 2s 35c battery right now and it works great. I have heard that higher c rating is better, but the other day I looked at the specs of the motor and esc and it says it can only go up to 50a. C rating I believe stands for continuous amps. So if doubled it, it would be 70c and I could be looking at another fried esc and maybe no warranty which would really stink. Please tell me if I am correct in assuming that higher than 50c would blow the system out.

    Thanks!
    Batteries don't push current (amps) the motor pulls current and the esc acts as a regulator in a sense to give the motor what it demands per given voltage. This is why its recommended to have to higher rated C battery than what the motor can pull per given voltage. Look at a motors specs just as a example a motor rated at 75a max with rated max voltage of 12.4v. This is what the motor is expected to pull 75a when given 12.4v so given 8.4v the motor will pull less current (amps).

  3. #3
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    So if i'm using 70c it should be fine?

  4. #4
    RC Turnbuckle Jr. Petertje60's Avatar
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    C rating can simply never be too high, it tells you something about the ability of the battery. You have to multiply it with the capacity of the battery to get the maximum current that it can deliver.
    So a 2500mAh 50C is able to deliver 50 x 2500 mA = 125000 mAh, which eaquals 125A.

    So if your ESC can handle 50A, you have to find a battery that is able to deliver that current, or better, more than that.

    I have had a lot of discussions about how electrical current works. Best is to compare the system (battery, ESC, motor) with a system that uses water.
    A battery is like a big balloon with water in it, which will push water out if you let it.
    The ESC is the tap which controls the amount of water which comes out.
    The motor is a lawn sprinkler.

    The pressure in the balloon tells you something about the voltage, the width of the nozzle about the current. The balloon size is the capacity.
    The width of the tap tells you something about the amount of water that can go from the balloon to the sprinkler.
    The size of the sprinkler tells something about the water it can bring to the lawn.
    Nobody is born with experience

  5. #5
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    Quote Originally Posted by Petertje60 View Post
    C rating can simply never be too high, it tells you something about the ability of the battery. You have to multiply it with the capacity of the battery to get the maximum current that it can deliver.
    So a 2500mAh 50C is able to deliver 50 x 2500 mA = 125000 mAh, which eaquals 125A.

    So if your ESC can handle 50A, you have to find a battery that is able to deliver that current, or better, more than that.

    I have had a lot of discussions about how electrical current works. Best is to compare the system (battery, ESC, motor) with a system that uses water.
    A battery is like a big balloon with water in it, which will push water out if you let it.
    The ESC is the tap which controls the amount of water which comes out.
    The motor is a lawn sprinkler.

    The pressure in the balloon tells you something about the voltage, the width of the nozzle about the current. The balloon size is the capacity.
    The width of the tap tells you something about the amount of water that can go from the balloon to the sprinkler.
    The size of the sprinkler tells something about the water it can bring to the lawn.
    Thanks! Never really thought about it that way. That helps alot!

  6. #6
    RC Turnbuckle Jr. Petertje60's Avatar
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    Quote Originally Posted by MiniSummit50Mph View Post
    Thanks! Never really thought about it that way. That helps alot!
    No problem. Glad it helped!
    Nobody is born with experience

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