Why is 6s easier on an esc compared to 4s
 

I am trying to understand why 6s is easier on a esc compared to 4s. If this is the case why are esc only rated to 6s generally? Wouldn't more cells make it easier on the esc, for example why cant we run a 12s on a tekin/mmp? I realize a 12s wouldn't fit any buggy or truggy but for arguments sake. I am not trying to start an argument I am trying to understand this concept. I spoke with Castle Creations and they told me that 4s is easier on the esc than a 6s, maybe he didn't understand my question. thanks for your help

It depends on the motor being used. For example, if you run a 2100kv motor on 4s, that would be within acceptable limits. However, if you run the same motor on 6s, obviously, there is much more strain on the ESC.

But lets say that you want to run around mid 30's in MPH, the setups are as follows:

2100kv motor with 4s(14.8v) battery = 31080rpm

or

1400kv motor with 6s(22.2v) battery = 31080rpm

So with the car and the gearing being equal, top speed should be the same. In the above examples the 6s system will pull roughly half the amps of the 4s system, which is easier on the ESC. It also allows you to run a lighter, low Mah battery and still achieve roughly the same run times. The two different setups will also drive differently, because of the different torque and power curves of the motors. These are just examples of what's possible, so don't flame me for missing something.

I could be way off here, but I have been looking into this as well.

I dont think 6S is easier on an ESC. The only advantage of running 6S, over 4S, is you can go with a lower kv motor & still get the same performance, which, with the lower kv motor, would be easier on the esc.

the higher the voltage, the lower kv you can go. The lower the kv, the less amp draw you pull which = less heat for both motor & esc.

If I am wrong, I'm sure someone will chime in as I have been trying to understand this myself. I am considering going from my 4S / 2000kv setup in my truggy, to a 6S 1350kv setup.

EDIT: reracer beat me to the punch!

Exactly, it is all physics really. Power= Amps x voltage . More voltage nets you the same power while pulling less amps than a lower voltage setup would.

Power = current X voltage
Power is what it takes to move the car so if power remains constant then when voltage goes up, it takes less current to make the same power. Current is what heats everthing up.

My Mugen 5S 1700KV burns around 240mA/minute
My Mugen 6S 1400Kv burns around 190mA/minute

They are both faster than they need to be.

In addition as you go up in voltage & down in motor KV the car gets smoother. Nothing is smother than my 6S setup.

Now, if we could only get ROAR to see the light...

The info just listed should be made a STICKY at the top of every single brushless conversion thread. :nod: I can't tell you how many times I've had to explain this. :lol:

I will add that I'm down to 2200mA on my 6S set up & still make 10 minutes eveywhere I run. The pack is something like 373 grams. This car is now under 7lbs 3oz & perfectly balanced.

http://www.rcdude.com/servlet/the-16...X--dsh-/Detail

so how will a 4s 1900kv set up compare to a 6s 1400kv setup esc temp wise. I already know the difference in performance.

Voltage is your friend. The motor won't necessarily run cooler, but the ESC and batteries will definitely thank you. You can get away with lighter batteries, less mah for same or longer runtime, and lower C rated packs.

Yup, all you need is a 6s 2200 pack for most tracks to run 10 minute mains. If you are racing with nitros and need lightweight setups for 15 minute mains, higher voltage is the way to go. If you run a 20 minute main, you definitely will need to run 5s and 6s to do it reliably.

I haven't found a significant difference in how the cars drive as you go up in voltage and down in KV. The bigger difference to me just seems to be what RPM you are targeting with your motor and voltage combination.

30,000 rpm = 30,000 rpm regardless if you do with a 2650 on 3s or a 4s 1900 or 5s 1550. The only difference is the mah you need of your battery to get the same runtime across setups.

3s 8000 = 4s 5000 = 6s 3000 generally speaking for run time.

Well without much thought it's easy to see why. The only technical (electronics) guy on the baord only makes a 4S controller.

X Files conspiracy music playing in the background... I would hate to think that is the reason, but ROAR really hasn't given any logical reasoning why the batteries are limited to 4s and hardcases other than "because we say so".

That's about on par with the ROAR mentality....

Not such a long reach though is it?

Ok, along these same lines, how about going from a 4s/1900kv setup to a 5s/1900kv setup, BUT, also going from 16/48 gearing to 15/50 gearing?