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What C Rating Do Most People Run?

What C Rating Do Most People Run?

Old 04-07-2011, 02:45 PM
  #16  
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Originally Posted by daleburr View Post
A motor will only draw the current it needs. If a motor needs 80A and the battery can only provide 60A, then going to an 80A battery will provide more power. However going from there to a 120A battery would provide no increase in power, as the motor won't use the extra current the battery could supply.

Thats why some people see a difference when they go for a bigger C rating, and others dont. It all depends on what your motor needs (which in turn depends on the class, gearing, ESC settings and driving style).

For my 10.5TC I tried going from 40C to 60C and saw no difference in power. The data logger shows I never pull more than 70A, which the 40C packs are more than capable of providing.
You always have one of the most sound answers. Thank you.
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Old 04-10-2011, 06:47 AM
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I run 50c on silvercan. Makes a big difference.

It's not the amp draw.

It's simply the newer 50c packs have higher average discharge voltage than older 25c/30c packs.

Example:

Orion 25c = 7.2v
HiEnergy 50c = 7.8v

That is 0.6v difference or around 8% difference in battery voltage.

In silvercan, 8% advantage in power is huge.

Hope this helps.
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Old 04-10-2011, 06:57 AM
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The way I understand it, for stock racing there's jsut no way anything over 25C could give any advantage, all other things being equal.

But the latest " crazy Cs " batteries have a way lower inner resistance and that makes a huge difference no matter what motor you run, wherehas " big Cs " can be appreciated only in mod- someone correct me if needed.

Not sure I understand the last comment about Voltage, though. All my batteries are charged up to 8,4V.
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Old 04-10-2011, 07:42 AM
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Hi,

Yes, we charge lipos to peak at 8.4volts.

But as soon as you connect a load (e.g. motor), some batteries will supply an average of only 7.2volts, some 7.8v, etc.

From my experience, the newer batteries supply higher voltage under load. Which might explain why people prefer 50c (i.e. newer battery technology) than old 25c.

You can do a simple test. Connect your race motor to a slave motor. Put a voltmeter at the output of the slave motor.

Then put a 25c battery to your race motor, take the voltage reading at the output of the slave motor.

Then do the same test with a 50c. Chances are you will get higher voltage reading at the output of the slave motor with a 50c, meaning the slave motor is spinning faster with a 50c.

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Old 04-10-2011, 08:02 AM
  #20  
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rccartips, Thanks for shedding some light on this subject. Stock motors need all the help they can get (more voltage under load). I believe most people on here that say they feel no difference in higher C batteries are running low turn Mod. motors and are already blisstering fast.
Tom
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