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C rating, Battery MaH and Punch...

C rating, Battery MaH and Punch...

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Old 04-21-2011, 01:11 PM
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Default C rating, Battery MaH and Punch...

Okay, I am by no means a new racer or new to lipo

BUT

I ask the experts (all of us, we use this stuff each time we hit the track)

WHY

would a 5000 20C (100 amps) pack have more/less punch than a 4000 25C (100 amps)...take your pick of any 2 lipos with same amp ratings.

I can buy into the weight factor, so that aside....

Especially looking for input from racers that have run something similar to this back to back, to see the "feel" difference.

NOT

looking for Brand A is better than Brand B, but more overall knowledge gain...everything else being equal or at least similar.
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Old 04-21-2011, 01:27 PM
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Originally Posted by jk racing View Post
would a 5000 20C (100 amps) pack have more/less punch than a 4000 25C (100 amps)...take your pick of any 2 lipos with same amp ratings.
so i think this is correct. the 1000 mah diff makes up in C thus having the 25c the same... in a nut shell...amps are amps, only thing that could restrict this would be a smaller diameter wire causing drag. the mah rating has some effect on the power. i've noticed running a 5000 compared to a 5600 w/ the same c rating. hope this helps and hope i am right!
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Old 04-21-2011, 01:28 PM
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Less. Seems C is the dominating factor, since it has an inverse relationship with Internal Resistance. Lower internal resistance equates to more punch. Lower internal resistance results in higher voltage maintained under load, thus more punch.

The max amp thing is not the key here, as I assume you are primarily interested in punch with a stock/spec motor. The amp load being way below the max ratings, is not so important.

This has been my experience both with on track performance, ability to make large jumps and such with stock motors, and reinforced with bench testing.

Last edited by Dave H; 04-21-2011 at 04:20 PM.
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Old 04-21-2011, 01:33 PM
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^^ ya^^
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Old 04-21-2011, 01:35 PM
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Originally Posted by jk racing View Post
Okay, I am by no means a new racer or new to lipo

BUT

I ask the experts (all of us, we use this stuff each time we hit the track)

WHY

would a 5000 20C (100 amps) pack have more/less punch than a 4000 25C (100 amps)...take your pick of any 2 lipos with same amp ratings.

I can buy into the weight factor, so that aside....

Especially looking for input from racers that have run something similar to this back to back, to see the "feel" difference.

NOT

looking for Brand A is better than Brand B, but more overall knowledge gain...everything else being equal or at least similar.
The mah is like the size of a fuel tank. The higher c discharge the pack is; the faster you CAN (drain the available fuel.)Or amps. If you try to draw too much current (or fuel) from a pack with a lower (c rating) You will have a drop in voltage. Which equals less avalible power. Thats why a 4000mah pack (20c rating) will feel less powerful than a 3000mah pack with a (40c rating.)
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Old 04-21-2011, 04:15 PM
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Originally Posted by arrtay View Post
Thats why a 4000mah pack (20c rating) will feel less powerful than a 3000mah pack with a (40c rating.)
That example shows 2 quite different batteries IMO. One only has a 80A discharge rate while the other has a 120A one. The 4000Mah lipo will have longer runtime, thats it.
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Old 04-21-2011, 04:39 PM
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Originally Posted by Dave H View Post
Less. Seems C is the dominating factor, since it has an inverse relationship with Internal Resistance. Lower internal resistance equates to more punch. Lower internal resistance results in higher voltage maintained under load, thus more punch.
thanks Dave, that is exactly what I have felt in my experience also. Within reason, a higher C battery will "feel" more punch than a lower C battery. (Hence the thread overall)

I have run 3200 25C (80 amp) back to back with 3600 20C (72 amp) and could feel a difference in the punch (the 25C packs being years older).

But, I also have some 5400 24C (Older Checkpoints, I think they are 24C) packs that have great punch. Feel as good as my Reedy 35C.

Yes, I mainly run non boosted 17.5, occasionally a 13.5 or VXL motor.
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Old 04-21-2011, 04:41 PM
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Originally Posted by Dave H View Post
Less. Seems C is the dominating factor, since it has an inverse relationship with Internal Resistance. Lower internal resistance equates to more punch. Lower internal resistance results in higher voltage maintained under load, thus more punch.

The max amp thing is not the key here, as I assume you are primarily interested in punch with a stock/spec motor. The amp load being way below the max ratings, is not so important.

This has been my experience both with on track performance, ability to make large jumps and such with stock motors, and reinforced with bench testing.
correct!
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Old 04-21-2011, 09:51 PM
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Originally Posted by Dave H View Post
Less. Seems C is the dominating factor, since it has an inverse relationship with Internal Resistance. Lower internal resistance equates to more punch. Lower internal resistance results in higher voltage maintained under load, thus more punch.

The max amp thing is not the key here, as I assume you are primarily interested in punch with a stock/spec motor. The amp load being way below the max ratings, is not so important.

This has been my experience both with on track performance, ability to make large jumps and such with stock motors, and reinforced with bench testing.
^^^correct again, couldn't put it better myself.
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