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lipos: C ratings and runtimes

lipos: C ratings and runtimes

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Old 04-09-2012, 08:50 AM
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Default lipos: C ratings and runtimes

Just wanted to know if I'll get better runtimes running a 30C or a 50C battery of the same brand and capacity
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Old 04-09-2012, 09:06 AM
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Originally Posted by Pulse_ View Post
Just wanted to know if I'll get better runtimes running a 30C or a 50C battery of the same brand and capacity
same run times
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Old 04-09-2012, 09:18 AM
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Ok, so if I want a light setup I can go with a low C rated battery?

I used to run 6S Hyperion G3 lipos in 25C 3300mah. So I had 3.3A x 25 = 82.5A. I never had a single issue but I read guys advicing much higher C ratings to have more amps.

I'm about to pull the trigger for 3300mah 5S 25C lipos but I just need to make sure it's safe for the system. The brand is Gens Ace and I manage to get 12 minutes runtime in 2200mah 5S 55C which is awesome for a 296g battery. I just need 3 minutes more to complete my races
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Old 04-09-2012, 09:30 AM
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Originally Posted by Pulse_ View Post
Just wanted to know if I'll get better runtimes running a 30C or a 50C battery of the same brand and capacity
Originally Posted by Cpt.America View Post
same run times

HIGHLY dependant on your application.

In a 1/8 or 1/10 4x4 you will ABSOLUTELY get longer run times with higher C rated packs, but you MUST consider there is no standard to "c" ratings and one companies 150c may only be equal to another companies 30c.

Why you ask?

Simple.... Higher C rated packs are capable of handling higher amp draws while maintaining the voltage. Voltage cut off's can be hit before a packs mAH is fully used, this happens often in high draw systems. If your lipo is getting really hot or poofing or not making full mAH you KNOW you need a higher C rated pack. What happens is as voltage drops, amp drawe goes up, as amp use goes up heat goes up. At any rate, the longer a pack can hold voltage the more likely you are to have the use of every bit of mAH the pack is capable of.

So YES you almost always get more run time, and you almost ALWAYS get a punchier response as the packs can provide the needed amps through the entire run before your ESC hits LVC.

lets say you need 1000watts for your top speed down the straight..

while voltage is peaked...
16.8v x 59.5amps = 1000watts
after racing a bit
14.8v x 67.6amps = 1000watts
near LVC
12.4v x 80.6amps = 1000watts

This is just showing what happens with the amperage draw as you work through a pack. Obviously higher C rated packs can provide this amperage better and longer. mAH * C rating = approx amp draw capability (again factoring in false C ratings.. no packs can sustain 150c as some company's list ;P)


Originally Posted by Pulse_ View Post
Ok, so if I want a light setup I can go with a low C rated battery?

I used to run 6S Hyperion G3 lipos in 25C 3300mah. So I had 3.3A x 25 = 82.5A. I never had a single issue but I read guys advicing much higher C ratings to have more amps.

I'm about to pull the trigger for 3300mah 5S 25C lipos but I just need to make sure it's safe for the system. The brand is Gens Ace and I manage to get 12 minutes runtime in 2200mah 5S 55C which is awesome for a 296g battery. I just need 3 minutes more to complete my races
Any time you drop voltage I would increase "C" rating to compensate as you have noted you will need more amps available if you are asking for the same amount of power (same weight vehicle, same basic top speed, same track conditions)
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Old 04-09-2012, 01:28 PM
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+1 on what 8ight-e said!

In simple terms, the higher the C rating, the easier it is for the battery to put out the required amps. In addition, as the pack ages, it will still be capable of producing thos run times needed because although the capacity will have dropped slightly, it will still be able to supply the necessary power.

I have 5 packs. 2 are Gens Ace 40c and 3 are Nano Tech 45c. They both have plenty of punch and will provide double what my VXL systems can draw. In my Slash (and my kid's trucks) generally something is breaking before the pack is dead. LMAO
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Old 04-09-2012, 02:02 PM
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higher the c rating the better! as long as its a TRUE c rating!
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Old 04-09-2012, 06:33 PM
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Up to a point. In reality you can only draw so much through the wires, connectors and other parts of your system without damaging them first. A 5000mAh pack truly rated at 60C is actually 300 Amps of current. That's a lot of juice, and your speed controller is rated much lower.
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Old 04-10-2012, 04:48 AM
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I agree with the last post. 60C is useless to me. Actually anything over true 45C is. I just don't need it. I run a gens ace 55C to compensate the low amperage of my 5S lipo which is only 2200mah but that's it. With bigger lipo I prefer having a true 25C hyperion than a 40C bad lipo. There's no standard for C ratings anyway, that's just marketing. I ran a 12h endurance with 3300mah 25c hyperion lipos with no troubles at all. Sometimes less C is better, car is more controllable and weights less. You just have to find the sweet spot. I think drivers should care more about the weight of their cars rather than the power.
The thing is there is a bottom limit of course and I hesitate to go for a 3300mah 25c lipo in 5s because I'll only reach 82,5 amps. 5S lipos are quite hard to find so if you have any suggestion of brand that offer good quality for the price.. I really like gens ace but I can't find a 5S lipo over 25c
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