In regards to LiPo batterys "C" is Capacity And is used in regards to the output of the basttery. A 1-C rated 1000 mAh LiPo battery can be discharged at 1 Amp without damaging it. The same capacity LiPo rated at 25-C cam be discharged at 25 Amps. A common battery pack for a 600 size Heli is a 4200mAh 22.2V,6S LiPo pack rated at a 70-C surge rate. That comes out to 294Amps surge current. We do cary larger electric Heli"s and the batterys are much larger. Yes they are expensive but with Heli's the power to weight ratio is critical. I work at a locak Hobbyshop and deal with this daily.
----- Original Message ----- From: "Clark Ward Jr" <[email protected]> To: <[email protected]> Sent: Sunday, October 18, 2009 7:59 AM Subject: [TANKS] Re: fuel for my tank > > C is a physics term for Coulombs; an Amp is 1 Coulomb per second. > Or, 1 C = 1 Amp*second, so I guess if a battery was rated at 100C, you > could push it to 50A for 2 sec before bad stuff happened. (That last > bit is speculation, I'm not a LiPO battery expert, the price always > turned me off ;) > Even NiMH would be spendy for a tank...Figure a 10AH D-cell NiMH at > 1.2V costs around $6 in bulk. Say you wanted 24V and 20AH, that's > US$6 x 20 x 2 = US$240 just for one battery, not counting putting it > together or paying someone to do so. For that price, a > non-lottery-winner could buy 4 lead-acid batteries. A comparable pack > of LiPO batteries (just googled it) would be six 11.1V 3.4AH packs, > three parallel strings of two in series, at $70 each, for a total of > $420. That is fast approaching the rolling chassis investment of my > Sherman. It is also only rated at a discharge of 36C. I'm fairly > sure that astarting a tank from a halt will require more than 36A for > more than one second (okay, maybe less amps, but not many less). If > you draw more than 18A for 2 seconds, you are in the danger zone with > a $420 battery. > > While the exotic is cool, the more mundane gets the job done, cheaper. > > -- > Clark in Georgia who needs to get his tank moving so he can talk smack > to Copperhead > > > --~--~---------~--~----~------------~-------~--~----~ You are currently subscribed to the "R/C Tank Combat" group. To post a message, send email to [email protected] To unsubscribe, send email to [email protected] Visit the group at http://groups.google.com/group/rctankcombat -~----------~----~----~----~------~----~------~--~---
