LiPo for the rooster Crawler...
 

I'm looking for a LiPo for my ax10 with the rooster crawler and novak 55t motor...

4 wheel steering, VF Dig (if i can find one)

The bnovak instructions/website say "Input Voltage: 4-7 Ni-Cd/Ni-MH cells (1.2V/cell) or 2 Li-Poly cells"

http://www.teamnovak.com/products/es...ler/index.html

I see alot of people running 3 cell lipo's... But the site says 2 cell...

Can someone point me towards a decent battery.. at least spec wise, and I can find the dimensions i need... Prefer to buy the correct batteries the first time...

i did find this...
http://www.rccrawler.com/forum/showt...t=lipo+rooster

Hit up the guys at Maxamps.com - they can do just about anything Lipo for you.

Heres a good start.http://www.cheapbatterypacks.com/mai...&man=TP&cat=PL I ran the 2s 1320 mah on my rooster and still run it with the goat.

what does a bigger 'mah' do for you?
say the 2000 mah

More mah is more runtime in a crawler...

So I can get a 2s with a higher mAh rating and get a longer run time...
The mAh is the 'gas tank size' in a way then...

I guess the 2s or 3s is the volt rating, as from what I'm seeing on that site above it looks like 3s batteries have a higher voltage output... ?

im not a lipo guru by any means. my understanding was the "S" is about cell count, ie 1 cell, 2 cells 3 cells, and the "C" is about drawing amps????
not sure the S is about voltage (but may be).



so a 2s 21C lipo is a 2 cell 21 amp drain? am i understanding this correctly? and becuz its 2 cells its 7.4v.


arnt all lip cells 3.6v per cell? so any 2 cell lip is going to be a 7.4v pack?

More Cells generally gives higher voltage. same as a NiCd or NiMH pack does. MaxAmps list 2S at 7.4V, 3S at 11.1V, and 4S at 14.8. That works out at 3.7V per cell.

The 'C' number I believe is the 'Coulomb' measurement. Coulombs are units of electrical charge, Volts = Joules of energy per Coulomb, and Amps = Coulombs per second. I would think them that the 'C' rating is the number of Coulombs the pack is capable of throwing out in a burst without divorcing it's sensibilities keeling over.
Why they didn't just refer to it as Max Amps, like they do on car batteries, beats me, there's probably some (ir)rational scientific explanation. ;)

The guess I'd hazard that the maximum Coulomb output is not time dependent as it may occur over less than a second, and still cook the battery. Think, if you draw 30C for 1/2 a second and non for 1/2 a second you're only drawing 15Amps (0.5s x 30C) but you've exceeded the maximum output of a 25C battery pack.

DISCLAIMER: non of the above is fact, or based on any knowledge, other than me guessing based on my college education in Physics...

The S stand for cell count. 2s, 3s and so on stands for 2 cell, 3 cell and so on. 3.7v per cell is correct. That's nominal voltage. They actually charge to about 4.2v per cell.

The C stands for constant amp out put. You multiply the packs rated mah times the C rating to get the constant amp draw the pack can supposedly supply. Example. A 3s 5000mah 10C battery will provide 11.1 nomimal volts at a constant amp draw of 50 amps. 5000mah x 10c = 50amp. A 3s 5000mah 20C battery will do 11.1v at a constant 100 amp draw. 5000mah x20c = 100amp. There is usually a listed burst value on the lipo too. This is usually about one and a half times the C rating.

Votls x amps = watts.

Higher voltage will be better for your battery as too much of an amp draw to make up for the demanded wattage of your motor is harder on your battery. Plus, a higher voltage battery will give your 55 turn, 45 turn or whatever motor you're running more wheel speed.

As far as the Rooster goes, my friend runs a 3s 2000mah 25C lipo and has nothing but trouble. I don't know what tricks are being used by others to run a 3s lipo on a rooster. I imagine running a fan on the heat sink is a good place to start though.

For the crawler application, most any lipo will suffice as there isn't a huge amp draw from these motors. I would go for the best price. Cheapbatterypacks.com, TrueRC.com or SPCRacing.com all offer great lipos at great prices. Max Amps is going to be a good battery, for this application, but their batteries are a lot more expensive.

Check out SuicideNeil's Emaxx FAQ here: http://www.robotwars.00server.com/emaxxfaq.html
Not all of it applies, but the info about Lipos and lipo chargers does.

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I've been happy with my LiPos made by TrueRc.com.

the s does not stand for cells. it stand for series. so if you got a 2s that means 2cells in series. if you got a 2s2p thats 2cells in series and 2cells in parallel. series means voltage adds together mah stays the same and parallel mean mah adds together and voltage stay the same."thumbsup"