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Old 10-29-2008, 03:39 PM   #1
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Default What is the lowest C rating I should look at for a LiPo?

Amain has ProTek R/C 2S Li-Poly 15C Car/Starter Box Battery Pack (7.4V/4000mAh) for 40$

NOTE: These batteries only have a 25C burst rating, so they are not particularly good for high current draw applications such as brushless 1/8th scale buggy and truck conversions. They work awesome for 1/10th scale 2wd and 4wd applications, but not for 1/8th scale. We recommend you use a 30C constant current battery for 1/8th scale brushless applications.

This seems like a great price for a few batteries to practice with....but is the 15C rating too low?

This would be for a brushless 2WD vehicle
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Old 10-29-2008, 03:50 PM   #2
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it depends on what you're useing it for. for a 10.5 or slower 25c or 30c is what all the guys at my track are running. for 8.5 or faster 15c or 20c is sufficiant. for eighth scale electric i'd assume you want a lot of power and a good amount of run time so 20-30c with 4000+ mah should be good. i could be wrong on the eighth scale but it sounds right considering you want speed and time. oh yea i'm not pos. but you might want to try a 3s 11.1v lipo for eighth scale although i'm looking at the orion 3200 3s 11.1v for my 2wd not sure but it might be good.
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Old 10-29-2008, 03:55 PM   #3
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It depends on the brushless anything above a 6.5 will be fine anything below might be slightly lacking but still fine if your running a mamba of 4600 or 5700 I reccomend at least 20 c 4000 anything faster 6900-7700 I recomend 30c 3600 minimum
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Old 10-29-2008, 03:55 PM   #4
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Originally Posted by gweed View Post
it depends on what you're using it for. for a 10.5 or slower 25c or 30c is what all the guys at my track are running. for 8.5 or faster 15c or 20c is sufficient.
I think you have that flipped, but I get it
10.5 or slower 15c or 20c
8.5 or faster 25c or 30c
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Old 10-29-2008, 03:58 PM   #5
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Originally Posted by y2kgtp View Post
I think you have that flipped, but I get it
10.5 or slower 15c or 20c
8.5 or faster 25c or 30c
no the other way around
10.5 or slower the higher the c rateing (20+)
8.5 or faster the lower the c rateing (20-)
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Old 10-29-2008, 04:09 PM   #6
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Actually your wrong. The lower the turns the higher ampdraw needed. More c = more amps available. Example. Let's say two guys are running 10.5 one guy has a 30 c 4000 and another has a 20 c 4000 if they are geared the same let's say. 19/87 in a t4 the guy with the 30c won't have any more power than the 20 c guy since the ampdraw on the system doesn't exceed the 20 c rating. But if they were both running let's say a 5.5 the guy with the 30 c would have the clear advantage not only in punch but also in top speed. Due to its ability to hold voltage under a higher load where as the 20 c pack would struggle due to its lower amp(c rating ) because the 5.5 would draw much closer/over the c rating
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Old 10-29-2008, 04:16 PM   #7
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It doesnt metter what motor you have, i seen people run 30c on a 8.5 and doesnt hurt the motor. I run a 10.5 on a 25c lipo and have no problem, you are going to want a higer C rating on a bigger motor. On a bigger motor on a small C rate lipo you will over heat the lipo and can damage it, you can run a high C rate lipo on a small motor like a 13.5 or a 17.5 you will just have you gear down 1-2 teeth
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Old 10-29-2008, 04:22 PM   #8
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In a nutshell...

a 13.5T will draw less current than a 8.5T Therefore will require a less C rating of the battery.

These seemed like a great deal for practicing with....just gear down a little bit and I think they should be fine......
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Old 10-29-2008, 04:22 PM   #9
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Its not a matter of damaging the motor its a matter of having the punch/speed to keepp up. And not killing the lipo but unless he's running a 5.5 with a 10 c 1000 pack don't worry. My buddy runs a 2100 lipo 15c in his 10.5 buggy with no problems just lacksa a lil punch
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Old 10-29-2008, 04:36 PM   #10
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Some of the guys at my track (small indoor) won't use the higher C rated batts with a low turn motors. Too Much Punch. Lower C rating makes the low turn motors drivable. For 10.5, 13.5, 17.5, 25C and 30C is a good thing since the motor isn't insane fast already.
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Old 10-29-2008, 04:44 PM   #11
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Originally Posted by jkas10 View Post
Some of the guys at my track (small indoor) won't use the higher C rated batts with a low turn motors. Too Much Punch. Lower C rating makes the low turn motors drivable. For 10.5, 13.5, 17.5, 25C and 30C is a good thing since the motor isn't insane fast already.
thats what i'm saying... i dont run my 3800 orion 30c on my 7.5 4wd its too much i run my 15c 4800 orion on that and my 3600 and 3800 on my 2wd 10.5. i have no problems and have used my 4800 on a 7.5 for almost a year now and its as good as new.
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Old 10-30-2008, 07:52 AM   #12
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thats what i'm saying... i dont run my 3800 orion 30c on my 7.5 4wd its too much i run my 15c 4800 orion on that and my 3600 and 3800 on my 2wd 10.5. i have no problems and have used my 4800 on a 7.5 for almost a year now and its as good as new.
So basically you're saying that your choosing your battery C ratings in order for it to act as a punch limiter or slipper clutch? Instead of choosing the appropriate motor for the job or adjusting the punch limiting on the ESC?

It seems to me to be the wrong way to look at this. I'd rather have good power (higher C rating) getting to my motor and tune it down with the ESC/ transmitter, or better yet have chosen the right motor for the job which won't need tuning down at all in the first place. That way you're not straining the battery and it will last longer.

Just my 0.02$

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Old 10-30-2008, 09:17 AM   #13
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GWEED has it right. use the higher C ratings for spec classes like 10.5/19t to deliver the punch. Use the lower 15 C packs for mod, where most of us have more motor than the track calls for anyway.
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Old 10-30-2008, 09:42 AM   #14
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Quote:
Originally Posted by CODMAN View Post
So basically you're saying that your choosing your battery C ratings in order for it to act as a punch limiter or slipper clutch? Instead of choosing the appropriate motor for the job or adjusting the punch limiting on the ESC?

It seems to me to be the wrong way to look at this. I'd rather have good power (higher C rating) getting to my motor and tune it down with the ESC/ transmitter, or better yet have chosen the right motor for the job which won't need tuning down at all in the first place. That way you're not straining the battery and it will last longer.

Just my 0.02$

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Naa you got it twisted,

First off limiting your C rating or "punch" has nothing to do with a slipper clutch or acting as one.

The reason for it is a mod motor has punch like anything 7.5 higher... especially in a 2wd. You will not feel a higher c rated pack as much as if you were running a higher turn motor with less "MOJO"

sooo...... if you have less motor you want the most "punch" you can get


Duh !
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Old 10-30-2008, 09:51 AM   #15
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Originally Posted by RB FIVE View Post
Naa you got it twisted,

First off limiting your C rating or "punch" has nothing to do with a slipper clutch or acting as one.

The reason for it is a mod motor has punch like anything 7.5 higher... especially in a 2wd. You will not feel a higher c rated pack as much as if you were running a higher turn motor with less "MOJO"

sooo...... if you have less motor you want the most "punch" you can get


Duh !
Perfect rbfive!! Plus dont forget to add that the increased punch with the higher wind motors and higher C rated lipos can be translated into increased gear ratio for more top end!
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