# 15C or 25C or 30 C



## desidriver

hi all,
can someone explain me the difference between C's in Li-Po batteries?
i mean i saw there are different types of 15C, 20C or 30C's...
thanks for hand


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## hankster

The C rating is the maximum sustainable discharge rate. An example being a 5000mAh 20C pack can be discharged at up to 100amps 5000mAh x 20). Generally the higher the C rating, the lower the resistance of the pack and potental better performance.


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## 420 Tech R/C

Perfect explaination as usual hank ! The only thing i would add is the "C" stands for continuous, as in a 5000mah 20c pack is capable of a 100A CONTINUOUS drain without damaging the battery as long as the voltage doesnt drop below safe levels (3.0-3.2 volts per cell depending on manufacturer)

so for example the orion 3600mah 30C pack is capable of (3.6A x 30) 108Amps continuous drain. Where one of the new SMC 4000mah 40C packs is capable of (4.0A x 40) a whopping 160Amps continuous drain!! It sound like overkill, but keep in mind in classes like stock , the extra amperage translates into more torque, which when coupled with a 17.5 means you can gear up for more top end speed!!!


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## desidriver

thanks hank and 420 tech....one more question...
is 5000mAh 15C better or 2200mAh 25C?
thanks


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## AEoffroader

The 15C 5000 can give 75 amps continuous and will have over twice the runtime. The 25c 2200 can handle 55 amps continuous.


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## desidriver

what do you guys prefer?
a Battery with higher Amperes per Hour or the "C" continuous rate?
thanks


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## swtour

desidriver,

What's your run application (What type of Vehicle, and what type of driving or racing?)

Mah is RUN TIME

C rating is LOAD.

So if I was doing 1/8th scale BUGGY and a wet heavy track - I'd be looking for the HIGHEST Rated "C" and mAh

if you are playing with something that's not real heavy, and not using a HOT "Modified" type motor...big "C" would be less important to RUN TIME for playing...


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## desidriver

damn SWTOUR...very nice explanation for a dummy like me 
so i'm a beginner in RC Vehicles,it was my dream to have a 1:10 Monsta Truck since i was a kid, but coz of financial problems, i could n't afford it, but now.
I'm not doing any Races yet, I'm from Germany and the area i belong, we don't have any track anyways....but i wish we had one...Now me a my friends are planing to make one...
at the moment i would prefer longer Run time and lesser time for recharging!!!
so after u'r reply, I'm gonna buy a 5000mAh 15C battery for a my Truck ...
thanks


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## ta_man

desidriver said:


> damn SWTOUR...very nice explanation for a dummy like me
> so i'm a beginner in RC Vehicles,it was my dream to have a 1:10 Monsta Truck since i was a kid, but coz of financial problems, i could n't afford it, but now.
> I'm not doing any Races yet, I'm from Germany and the area i belong, we don't have any track anyways....but i wish we had one...Now me a my friends are planing to make one...
> at the moment i would prefer longer Run time and lesser time for recharging!!!
> so after u'r reply, I'm gonna buy a 5000mAh 15C battery for a my Truck ...
> thanks


If less time for recharging is a consideration, you might want higher C-rated batteries. Most LiPos require that you recharge them at "1C" (mean 1 amp for every 1000 mAHr of capacity). So you would have to recharge the 5000 mAHr batter at 5 amps and it would take a little more than an hour from empty.

Newer batteries with higher "C" rates (like the SMC 40C) are rated to be charged at up to "2C". So for a 5000 SMC, you could charge it at 10 amps and cut your charging time down to a little over a half an hour. (This assumes you have a charger capable of 10 amp output.)

If the battery is not rated for 2C charging it could be damaged by doing that. So if reducing charging time is a consideration, maybe a high C rated battery would be better.


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## Mr. Mac

New Member: At Xmas, purchased 2, yes two, new QS8006 helis. Here's the problem, have replaced the blades, new balancer x2, rear tail motor x1, and now need new batteries. I'M fed-up having to order from China, and want to replace the Li ion batts with LiPo's. The QS has 14.8V 1500mAH battery packs. Whats the best choice, Turnigy or Gens Ace? Also not sure as to mAH & "C" size to use. I'm grounded, both planes no power to fly.


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