ignishen

Anyone have any links to a site that explains how to calculate current of my system? I'm running a TLR 22SCT RTC and would like to invest in a few LiPo batteries for racing. Would like to also make sure they'll work with any upgrades that may occur

Im currently running:Also, how charged batteries do you guys keep on hand for a typical race? Thinking of running in the Short Course Showdown at Trackside this weekend!

Pulse_

2 good lipos are enough

35C+ batts are ok, just make sure you buy from a good brand (smc, promatch, ip, sting etc..)

wittyname

iTrader: (4)

Here you go ... plug in your pertinants and such and voila !
http://scriptasylum.com/rc_speed/car_setup.html

ignishen

That's a cool link, but it's not calculating what I'm looking for. Trying to figure which C rate batteries to go with for my system, and any possible upgrades. I'm new to this, so I could be missing it as well.

predu

iTrader: (6)

if your running 17.5 you want the highest you can afford... that being said it only matters if the rest of your equipment is up to par (dynamite is not) along with your driving and setup skills

wittyname

iTrader: (4)

It shows constant amp draw and burst amp draw . That should be more than enough.

If your system pulls 100 amps . You need to be around 5000 mah at 20c or greater. 5000 mah= 5amps x 20= 100amps.

3000 mah= 3 amps x 35= 105 amps.

Examples , not recommendations

ignishen

So from what I was able to find I need to find a battery capable of providing at least 50A. Essentially anything at a 5000mAh of 10C or more should cut it. Probably going to go with a 30C as I found a few deals. That seem right?

PnchoPwr

iTrader: (19)

When running 17.5 motors, most people have found it the best practice to get as high of a c rating on a battery that you can get. More c rating = better punch on lower turn motors.

Beaker151

iTrader: (8)

I have been wondering if this would be useful in getting information about a system set up in a car.

http://www.skyrc.com/index.php?route...&product_id=46

wittyname

iTrader: (4)

You are on the money here. You do not want to be stuck with a certain battery that works in one truck , but down the road , wont work in another.

This has been a great choice for a lot of racers I know ,

http://www.smc-racing.net/index.php?...product_id=209

asc6000

iTrader: (15)

You're overthinking this. Just get a couple decent batteries for now, no sense spending big bucks until you really get back into it. And as we all know the "C" ratings are many times inflated and simply inaccurate. After some time you will know better what you need and along the way you will also be learning about modern lipos.
The big thing you need to concentrate on right now is good charging habits.

ignishen

I hear you. A guy at the LHS was telling me that if you're going to race you need at least a 5000mAh / 70C battery, which was an instant red flag as it just so happened to be the most expensive one they had. Knowing a little about electronics I could also tell he was blowing smoke as he kept saying that the battery pushed current based on it's C rating, and I knew for a fact that it's pulled by the system demand.

I ended up getting a pair of 5000 / 30C's to run around with. I'm sure they'll be fine for quite a while.

Hoese37

iTrader: (5)

C ratings mean nothing now. They are all calculated in a different way. That's the reason when 30C was the new big number, Maxamps could say theirs was 150C. Its all inflated jargon. C ratings will matter only when there is an industry standard way to measure them. But to answer the OPs question, just get as much C as you can afford.

Dave H

Actually the guy is correct on the basics. The battery is the power source, it does push current into the load of the ESC/motor system. The voltage is sometimes referred to as the electromotive force. The ESC/motor doesn't pull anything.

It's more accurate to say the impedance of the motor limits the amount of current the battery can push through the circuit. When a higher voltage is applied to the same ESC/motor system the current will increase.

Batteries experience some voltage drop under loading due to internal resistance. A higher real C battery will have less voltage drop, driving more current, and providing slightly more punch. (Also discharges slightly faster in the process, no free lunch)

The key word is slightly, the differences are noticeable but subtle. I agree with ASC6000, don't get too worried at this point, get out and run some laps. As lipos have matured the differences have narrowed some, a mid performance pack properly taken care of will likely be better than the greatest pack not taken care of.