Does a crawler need need a high C rating ?

[Frank211]

Does a crawler really need a high C rating ?

Does it matter if its 25c, or is more always better, like a 50c battery for your crawler? Just curious, cuz i read somewhere (social media) that it doesn't matter for a crawler. Is there any TRUTH to that ?

 

[tapped-out]

I know for a smaller battery like 450mah the higher the C Rating the better...
With my moa crawler using Holmes Hobbies br-mini esc's and puller 500 13t motors.
My 3s 600mah 25c batteries would cause brown outs (LVC in esc's).
Bought new nano tech 3s 450mah 65C-130C batteries no more brown outs.

So I'd say buy the highest C rating battery in your budget..

Although you probably could get away with 25C 3000 to 5000mah in a scale rig...

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[lonleycreeper]

To a degree.

A low capacity battery will need a higher c rating than a high capacity battery.

Eg. A 2000 mah will need 40c to provide 80 amps, compared to a 4000mah needing only 20c.

The "C" rating is how fast you can drain a battery the mah is how many amps it has stored.

This is a highly simplified explanation....

 

[lonleycreeper]

Oh and the formula is Mah x C rating /1000= amps

 

[Frank211]

Here's the comment.
I actually thought a HIGHER C-rating would be better in any RC , but probably wrong tho, sense im always still learning.

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[lonleycreeper]

As far as the battery releasing power. The C rating is how fast you can drain the battery without damage.

If you exceed that, say pulling 80 amps from a 40 amp rated battery, you will damage the battery and it will not last nearly as long as one not abused in this way.

I have several 2200 3s 30 c batteries that have lasted 4 years now, they are starting to show their age now and I will be retiring them very soon. they all have 300 to 400 cycles on them and all but two are starting to puff and not give full capacity.

 

[tapped-out]

What rig are you buying a battery for?
When I buy new batteries from now on I'm buying the highest C rating my budget can afford. I'd rather have a higher C rated battery and not notice a difference then buy a low C rated battery and have brownouts.

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[Browneye]

As far as the battery releasing power. The C rating is how fast you can drain the battery without damage.

If you exceed that, say pulling 80 amps from a 40 amp rated battery, you will damage the battery and it will not last nearly as long as one not abused in this way.

I have several 2200 3s 30 c batteries that have lasted 4 years now, they are starting to show their age now and I will be retiring them very soon. they all have 300 to 400 cycles on them and all but two are starting to puff and not give full capacity.

^^This.

It just means you can pull higher amps out of it without damage.

Same for charging C's - you can charge a higher one faster - but only as fast your charger can. A 10C charge rate on a 3000mah battery means you can charge it at 30 amps - but what charger can do that? If they don't indicate a charging rate C value then 1C - a 3amp rate for a 3Kmah pack.



Same for amp draw - you're not likely to reach high amp draw with your crawler and hence the comment.

It's also an indication of the battery pack performance, or capability. But really, for a crawler it's not likely to make any difference. For a race car definitely - can make a difference between smoking it or not.



Stick with the name brands from your favorite RC supplier and you should be good. I'm careful about not storing them in a charged state, using a 1C charge rate, and not over or under charging them - zero problems over the past two years at this. "thumbsup"

 

[Frank211]

What rig are you buying a battery for?
When I buy new batteries from now on I'm buying the highest C rating my budget can afford. I'd rather have a higher C rated battery and not notice a difference then buy a low C rated battery and have brownouts.

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I already have batterys , i just didn't understand if C rating was a big issue in crawlers, me personally id buy batterys higher than 35c rating .
Just didn't sound right from that comment that i asked about.

 

[lonleycreeper]

I have only seen about 20-25 amps being pulled on a crawler with a 35t brushed motor and 2.2 tires. That said, my brushless F150 can pull upwards of 60 amps. Esc is rated at 80amps. So I buy my batteries based on past experience and ratings of my esc.

A watt meter for Rc though is a very helpful tool in diagnosing and figuring out what a electronics system can handle.

 

[WHITE-TRASH]

C rating doesn't matter much until it is too low for the application. I've ran some cheap little 15c 1300 3s packs mixed in with 60c 1300 3s and while going slow there isn't any appreciable difference but once a full throttle burst is called upon the difference is very noticeable. The low c pack cannot discharge fast enough so the rig is sluggish compared to running the 60c pack.

 

[colbynobo]

Has anyone else ever watched the Exocaged RC video on this topic? I'd be curious as to what y'all think of his findings and testing procedures.

https://youtu.be/5KAnSHiQWRk

 

[Frank211]

Ok everything y'all sayin makes sense)usually does,lol) ,i kinda figured that,had an idea about it, i just wanted to hear it from the guys who know more about it, and i did.....ALWAYS many THANKS.

 

[Browneye]

Its like voodoo science. Lol
Mess up and POOF!!

 

[QuesoDelDiablo]

Has anyone else ever watched the Exocaged RC video on this topic? I'd be curious as to what y'all think of his findings and testing procedures.

https://youtu.be/5KAnSHiQWRk

In terms of actual scientific/engineering data collection; the test methods are garbage and the results are useless. Typical of most youtube stuff.

For proper testing like this you'd need at least 5-10 batteries of EACH type and each battery would need be of KNOWN use and life-span, better equipment (i.e. calibrated) for the actual testing.

The only thing his results tell you is that those batteries have those characteristics.

 

[mprudic0404]

Someone said it first, so i add to it again.

BUY THE HIGHEST "C" RATING YOU CAN AFFORD!!!
(within your budget)

3 main reasons -

1) at some point, you will upgrade your rc, and bigger/better equipment will be fully utilitzed.
2) Unlike solid/fixed lithium/limn cells 'think 18650, 20650,21700 etc..' LIPO batteries are ALL soft pouch types (even hardpacks) and the last thing you ever want to worry about is a overloaded/overused soft pouch of unstable lithium. (pull too much current from a lipo pack and it heats up- which COULD cause a thermal-run-away)
3) ANY rc can and will DRAW massive burst rates (crawler or not) under a stalled motor condition. To put this into perspective- think brushed motor- and the rotor gets locked- the physcial brushes are making contact with a dead short (winding) fighting another fixed perm-magnet. its rare a motor gets locked or froze, but what if a small rock got into your motor can? The ESC doesnt know, it just keeps switching (feeding) power, ramping up to meet the throttle positon.

My 4 year old somehow got this exact situation and kept pulling his TX trigger. while the stock 27t motor burned a winding. at the time, he was using NICD's so the battery didnt care, and even a cheapie ESC still puts out high instantious power. (NiCd's dont follow C ratings, because they can discharge MASSIVE current levels)

if you get a high C rating, your battery will be the last issue to worry about.

just my 2cents.

 

[Frank211]

And i actually thought having a higher C rating(more power) would run your electronics a lil easier, less strain on the electronics , more power, easier to run a winch ,lights ,etc all cuz its more powerful than a lower number C rating. That's what i always thought about lipos....lol

 

[Corrupt]

I think of C ratings like a pipe. A larger C rating means you have a larger pipe that you can put more amps through. If you have a tiny tank though (mAh), and the machine you are using pulls a ton of amps (in crawler situations, not likely) you need a large pipe (C rating) to compensate. Upgrade to a larger tank (more mAh), and the pipe (C rating) doesn't need to be as big.

Look up your motor and ESC specs. That'll give you a good idea of how many amps your system is dealing with. Then, get a battery that will provide those amps and then some, in case of stalled motors or anything like that mentioned above. I.E. if your motor pulls 50a continuous, the ESC should be at the very least a 50a ESC and your batteries should be able to provide at least 50a, but better to have some that provide 100a. Less stress on the electronics, less heat, longer life. "thumbsup"

-Corrupt

 

[carpetfuzz17]

Same for charging C's - you can charge a higher one faster - but only as fast your charger can. A 10C charge rate on a 3000mah battery means you can charge it at 30 amps - but what charger can do that? If they don't indicate a charging rate C value then 1C - a 3amp rate for a 3Kmah pack.

Check out the iChargers. They can charge 30 amps and up on a single channel "thumbsup"

 

[Xx Losungen xX]

A stalled motor creates the most torque it can, which means it draws the most current it can.

A battery doesn't supply current, current is product of the motor creating torque.

C rating is how efficiently and effectively a battery can handle the current demand before causing damage.

Higher C rating, less damage, more efficiency.

Doesn't matter what battery is attached to the motor, it's gonna demand the current it wants to torque it's trying too, even if it causes failure.

Don't romp on the throttle or stall the motor, should be safe with lower C ratings.

I bought some 45/90C 2200mah 3S for my rig and don't romp on it. That rating was a good compromise between value and longevity for my needs.

Not saying I'm an expert but this very basic electrical theory, I am a Master Electrician and have been for 12 years, this basic theory has served me well over the years.

Cheers!