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Thread: Why only 25c

  1. #1
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    Why only 25c

    What does Traxxas only make batteries with a 25c burst?

  2. #2
    Marshal ksb51rl's Avatar
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    It's 25C maximum continuous.
    I don't think you will get an answer here.
    Alt-248 on the number pad = °

  3. #3
    RC Qualifier Panamon Creel's Avatar
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    Quote Originally Posted by ttThree View Post
    Is 25C sufficient for modded e maxxes and revos, that weight more then stock? That is the question.
    I'd rather say the question is what continuous amperage draw do you actually have, what size of battery (or batteries) will fit and is there a weight limit for the batteries?
    i.e. a 10000mah 25C battery can provide you with 250 Amps continuous but may not fit the space you have and/or might be too heavy for your application

  4. #4
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    Here is the issue with a 25C battery....

    Panamon is correct but also incorrect...

    so a 5000mah battery can safely discharge 125 amps with 25C rating. However this is with a FULLY charged battery. When the battery is being used/run the mah get "used". So at the end of a run you only have 1000 mah left in a 5000 mah battery you now can only discharge 25 amps... This is where I believe the issue stems from...versus a 65C battery with 1000mah where it can discharge 65 amps.
    Last edited by RcManChild; 10-27-2016 at 04:25 PM.

  5. #5
    RC Champion trax de max's Avatar
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    The capacity is a nominal value. The C rate is just the number in which that company tested that particular battery with using their own testing method. Each company uses their own method. A 1000mAh 25C battery might well outperform a 1000mAh 65C battery, it's only on paper where it's different.
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  6. #6
    RC Qualifier Panamon Creel's Avatar
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    The C Rating current is based* of the rated Ah ( or mAh ) and not the available charge capacity of the battery. The ESR (Equivialent Series Resistance) will come into play in a partially discharge state of the battery which may limit the max current due to Voltage drop under load ( darn Ohms law ).

    *disclaimer the RC battery world if full of marketing hype with poor/no documentation on actual testing procedures/values/results from which the claimed ratings had been obtained from.

  7. #7
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    Quote Originally Posted by Panamon Creel View Post
    The C Rating current is based* of the rated Ah ( or mAh ) and not the available charge capacity of the battery. The ESR (Equivialent Series Resistance) will come into play in a partially discharge state of the battery which may limit the max current due to Voltage drop under load ( darn Ohms law ).
    The C rating is based off of rated mah, but as the mah diminishes so does amount of power available as the voltage drops.
    My main point is that if you have a 10000 mah battery rated for 25C, when it is fully charged you can potentially get 250 Amps discharge.... however with only 1000 mah left in the battery that number will be much less.

    *disclaimer the RC battery world if full of marketing hype with poor/no documentation on actual testing procedures/values/results from which the claimed ratings had been obtained from.
    Completely agree, although if you stick to the same manufacturer for batteries you can gain some reference of what the ratings mean within that company.

  8. #8
    RC Turnbuckle Jr.
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    Quote Originally Posted by RcManChild View Post
    ... When the battery is being used/run the mah get "used". So at the end of a run you only have 1000 mah left in a 5000 mah battery you now can only discharge 25 amps...
    This is completely not true! True C-rating wrt discharge is the rate of discharge of the cells, not the assembled pack and it is based upon the actual full useable discharge capacity of the pack, not the remaining state of charge at any given point in time. Any one who has tested Lithium-based cells at high discharge rates can easily verify this.

  9. #9
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    I was misinformed then and apologize. I rarely run my lipo's below 50% anyways to extend their life. That and when flying helicopters and planes you can't always land right when you need too so it gives me extra 2-3 minutes to land safely.

    In theory then the 8400 25C batteries made by TRAXXAS should not be puffing...

  10. #10
    RC Racer Killroy's Avatar
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    I have some max amps 100c batteries, and some traxxas 25c, can not tell the difference in performance, I think the Traxxas batteries perform better and cost much less.

    Sent from my XT1080 using Tapatalk

  11. #11
    RC Turnbuckle Jr.
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    Sorry to tell you, but you were taken when purchasing maxamps; or better named "Mini-Amps".

  12. #12
    Marshal ksb51rl's Avatar
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    Mini-Amps, lol, first time I've heard that one. They have really colorful pack wraps...
    Alt-248 on the number pad = °

  13. #13
    RC Qualifier Rich2's Avatar
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    Quote Originally Posted by °RcNightmare° View Post
    What does Traxxas only make batteries with a 25c burst?
    If you've sampled enough brands of batteries, you'll see that Traxxas
    batteries don't take a back seat to any of them. That's been my
    experience so far, but your's may vary. Another good question would
    be; why did Volkswagen diesels pass US emissions while others struggled.
    Honesty is the best policy. jmo

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