iThinman

I have a question. If the speedo/motor/gearing does not change and you step up from say a 35C battery to a 50C, and then to a 65C, would you expect 'more punch', 'more punch for longer' or both?

I was running a 30C and 35C in my 1/10, but recently replaced them with 50C. There is a noticeable increase in punch and speed for about 2 mins tops and then it flattens out (to a still very acceptable level).

So if draw remains the same, but the C rating increase, which would I expect?

whitrzac

iTrader: (97)

no...

because no 2s battery can deliver 200+ amps....


therefor the "C rating" system is flawed and invalid....

rcguy76559

iTrader: (22)

yes thats true but only if your motor can pull it. I have a 17.5 and i put a venom 3800 35c vs 5000 60c i cant tell a difference. But now with my mod motor in truck 6.5 same packs used before there is a difference. I prefer the lower c rating. Why theres less of a change in the first few minutes.

cliffhanger

iTrader: (11)

cool thanks for all these responses i'm thinking to go with protek rc 50c lipo i'm running 30c lipos now so should be a nice jump it take offs

cliffhanger

iTrader: (11)

any one tried to go from 50C to 65C?Did u notice any difference?

cliffhanger

iTrader: (11)

wow i just find this maxamps true 150C 7.4v lipo holy smokes

http://maxamps.com/proddetail.php?pr...4-Pack&cat=285

wallot

the 150 "TrueC" is just a marketing lie. those cells correspond to standard 25-30C cell rating

there is no standardized C rating so manufactures use whatever they want to sell their cells.

WillD

Correct me if i'm wrong, but one will only see much difference of a 65C pack compared to a 50C when higher powered motors come into play? I've seen real world testing in the past where 20-40C packs were compared and the 40C ones were only really beneficial with the hotter wind motors. With lets say a 13.5 motor, the performance increase with a 40C pack was very negligible.

wallot

of course that high C batteries are needed only for high power motors with very high AMP

for 300W 13.5t motor you can use 5000mah 20C battery and you wont see any difference in performance

I recommend using battery with continuous Amp rating same as Peak Amp that your motor needs.

For example if you have 750W motor (~100Amps at 7.4V) get 5000mah 20C or better

just beware that some vendors use burst C ratings to make their batteries look better than they are.

good vendor uses Continuous/Burst rating (45C/95C for example for Hyperion VX cells)

racer1812

iTrader: (31)

For those posting in this thread that ran NIMH back in the day, didn't you want the lowest IR packs you could find, no matter what class you ran? Stock or mod. lower IR increased performance. Way too many people are looking at the amp draw related to a packs C rating. A 5000mah 20C pack is going to run just fine in just about any racing class you run, stock or mod. but a 50/65 pack is going to show performance gains due to lower IR. C rating is directly related to IR IMO. To CLAIM the C numbers they do the cells have to have lower IR. IMO once you get to a 50/65 C rated pack the IR of the pack is no longer the choke point in the system as far as efficiency is conserned. Just my $.02 on the whole thing.

rccartips

iTrader: (3)

Hi,

Personally I've gotten better laptimes with a higher C rated pack using even Silvercan motors. Weak motors benefit greater from a better battery pack.

I don't worry too much about theories, it's easier to get actual results by testing on the track.

JEFFs SC10

iTrader: (15)

cool i'll be looking to pick one of these up.

There needs to be standardized way to measure C ratings. How can this be enforced?

wallot

i think only lots of independent tests showing how most of the cells are junk can force battery manufactures to adopt some standard ratings and add discharge graphs to the ratings.

what is the point of rating battery 50C when it drops to 3.3V under 50C load

batteries should not drop under 3.5-3.6 under defined maximum load

racer1812

iTrader: (31)

Lower IR in relation to performance isn't really a theory but I agree, put it on the track and see for yourself.

JFuel11

iTrader: (152)

I could not agree more to this statement!

I have raced onroad, carpet/dirt oval and offroad over the past few years with lipo batteries and this is the conclusions I have drawn myself:

25C or less does not provide the punch even in a stock class racing that a 40 or 50c pack does. It is not just about amp draw it is about teh Internal Resistance.

I moved from a 40C pack to a 50C pack last winter and noticed again even in a stock class an increase in punch. I look forward to moving into the 60 - 65c packs again not because of amp draw but punch that is provided due to the lower internal resistance.

If you are racing onroad/carpet or dirt oval where you need all you can get out of a battery/motor... Then you will notice the difference (assuming you are comparing an acutal 40c to a 50c). If you run in a loose dirt or lower traction racing such as offroad (Non Indoor clay) you most likely will not notice as much difference above 40C..

Just my thoughts...