View Full Version : 15C or 25C or 30 C


desidriver
05-06-2009, 10:58 AM
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

hankster
05-06-2009, 04:10 PM
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.

420 Tech R/C
05-06-2009, 06:43 PM
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!!!

desidriver
05-07-2009, 10:41 AM
thanks hank and 420 tech....one more question...
is 5000mAh 15C better or 2200mAh 25C?
thanks

AEoffroader
05-07-2009, 01:55 PM
The 15C 5000 can give 75 amps continuous and will have over twice the runtime. The 25c 2200 can handle 55 amps continuous.

desidriver
05-08-2009, 02:19 AM
what do you guys prefer?
a Battery with higher Amperes per Hour or the "C" continuous rate?
thanks

swtour
05-08-2009, 03:33 AM
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...

desidriver
05-08-2009, 11:12 AM
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 :)

ta_man
05-09-2009, 07:09 AM
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.