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Would to much of a C rated battery cause damage

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  • Would to much of a C rated battery cause damage

    I recently bought a plane at a fly-in from a guy and had a battery that was a high C rating that was used in a helicopter. It was a 4s which is what was used in the plane. It took off fine and I did go out a good distance and lost all signal. I later found out the receiver was really a park flyer instead of a full range receiver like I always have used. There was little to no damage but some dirt in the cowl. I cleaned it all up flushed the motor with electronic cleaner and put the battery also a full range receiver and now it doesn't have enough RPM to get off the ground. My question is would a high C rating battery cause and damage to the motor or ESC? I don't have it with me at the moment here, but I will all the rating. I do know it was a 4s 2800 battery.
    Still Learning:D

  • #2
    It had been said here before, The mah is the gas tank, the C rating is the fuel line, so no the C rating has nothing to do with the motor not coming up to speed, my guess ESC. Ron.
    AMA 424553

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    • #3
      After the crash, if you failed to close the throttle quickly, the motor or speed control may have overheated. I would guess the motor may be bad, perhaps some magnets came unglued. Notice any dragging when you hand turn the prop? Be very careful when testing motor and speed control with prop on, make sure prop adapter is on tight,

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      • #4
        Can't always go based on "dragging" felt when trying to turn the prop.

        Sometimes an ESC will shut down with MOSFETS activated, thus providing an electromagnetic resistance to turning the motor that can be surprisingly powerful. Some brands of ESC will have this happen more often than others (never seen it happen with a Castle ESC)

        So before condemning a motor... unplug the motor from the ESC and see if that makes a large change in resistance to turning the motor.
        You should still feel the "cogging" effect of the magnets lining up with the motor poles. Compare with the feel of a known good motor that is not connected to an ESC.

        Then there's the volt-ohm meter checks that should be done on the motor (again, not while connected to an ESC)
        FF gliders and rubber power since 1966, CL 1970-1990, RC since 1975.

        current planes from 1/2 oz to 22 lbs

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        • #5
          Thanks guys, sorry I haven't been on in a while. The motor spins actually free as it could. I did yesterday change out the ESC and it ran up handled on the ground as it should. I was doing some ground handling with it and all of a sudden it started smoking from the motor so immediately unplugged the battery and let it cool down and checked it all out. There was some discoloring as a charred look to some of the wires in the motor. So, I did plug the battery back in and tried it again and it ran up good again. I don't what's going on with this thing.
          Still Learning:D

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          • #6
            Did you check the specs of that plane to make sure it can run on 4s. Maybe the seller just flew it once or twice with the 4s when in fact, it was only meant for 3s. I had a Tundra that I just threw in a 4s one day and it made it to the second flight when out came a smoke trail and that was the end of the motor.

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            • #7
              It is specked for a 4s! You can find some of specs for it and I do have the book with it. Problem is, it doesn't give a lot info needed as to what size KV the motor is and no info what so ever on the motor give any indication as to what it is. I did pull the motor off, but couldn't remove the stuff off of the shaft to fit for the prop. I have a old Detrum motor off of a FW190 that should work. I changed the ESC to a ZTW 45a. The specs for the plane said a 40a was used.
              Still Learning:D

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              • #8
                I don't think you've mentioned what kind of plane it is.

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                • #9
                  ST Model is who makes it. Its a Acrobat 3D plane. Its pretty big and a heavy thing.
                  Still Learning:D

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                  • #10
                    It's not one of these, is it?
                    http://www.sheng-teng.com/products-AcroBat.html
                    They apparently have no 4s sport planes. I've had 2 ST Model planes .................... Flyzone Seawind and an old ST sailplane (now discontinued). Both were woefully underpowered. The Seawind, I upgraded the ESC and flew it as a 4 cell but I must admit that the motor and wires going into it got quite hot and I never flew it at max throttle for more than 10 to 15 seconds at a time.

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                    • #11
                      That looks like it. The wheels on this one are different and the specs I have call for a 4s battery. That's strange. The specs I have does say a it has a 40a ESC. I need to check it out a little more. The guy that had did say he always flew with a 4s battery. I'm getting a Flex QQ300 this weekend. That's what he got to replace this one. I have never flown a 3D plane. Just thought I would try a little something different. Thank You! I do know that Tower Hobbies was the one that carried this model.
                      Still Learning:D

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                      • #12
                        There are rare instances where the reduced resistance of high C rating can cause damage.
                        E=IR
                        E constant, R decrease, I increases...

                        There was a version of Cub RTF sold that had a marginal ESC. They sold a float kit that included a different prop and using that prop was enough to burn up the ESC. Tests showed appx 1 amp from damaging the ESC with the RTF package's prop on the OEM battery.

                        Cases like this, with the tiny margin could see enough increase in power passed through the ESC to burn it up.
                        Note that it would be a cheap ESC with no thermal protection. More often you'd see what appears to be a low voltage shutdwn, despite having a full battery, because thermal protection is used in more and more ESCs.

                        You have to be right on the edge of overloading already. But we have seen models shipped with low margin.
                        FF gliders and rubber power since 1966, CL 1970-1990, RC since 1975.

                        current planes from 1/2 oz to 22 lbs

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                        • #13
                          I looked back at the manual and it does call for a 4s 2200 and on the website link that was in xvipers post it call for a 3s. I'm friends with the guy that had this and he flown it on a 4s. I've messed with trying to get it figured out. If not it can hang in the shop. We shall see.
                          Still Learning:D

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                          • #14
                            According to that website, it has a 4015 - 800kv motor. Does your manual say it has the same motor? Offhand, 40A ESC would likely be enough for 4s on a prop plane. The question is, would that motor handle it, with the prop you're using?

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                            • #15
                              That has been my issue. My manual doesn't give info as to the KV on the motor or any such. I even emailed Tower Hobbies and they couldn't give any info and even posted on rcgroups several times with no answer. You have giving more info then any.
                              Still Learning:D

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                              • #16
                                If it were me, I'd go to HobbyKing and search out an outrunner motor with the same configuration (ie, wires coming out the proper end), having the same diameter and barrel length and a similar KV that runs on 4s, given the same prop you want to use. Their motors are fairly reasonable and tend to be somewhat stout.

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                                • #17
                                  Thanks Viper, I didn't even think about HK. I've searched MRC and Horizon Hobbies and Tower didn't think about HK. Thanks
                                  Still Learning:D

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