3S vs 6S question for your guys... - RC-Monster Forums

jzemaxx · **3S vs 6S question for your guys... -** 05.15.2009, 12:22 PM

Hey guys I currently run a setup that uses twin 3's 5K mah (10K total) in parallel. I was wondering if running a 6S 5K mah at 60% EPA vs 125% EPA with 3S would get me the same runtime? I am trying to shave weight, plus easier to charge 1 batt then 2 between heats. MPH with the EPA set at 60% was exactly the same as the 3S setup at 125% EPA....well within about 1-2 mph.

jzemaxx · 05.15.2009, 12:34 PM

BTW this is with a MMM 2200 combo.

Arct1k · 12:41 PM

Why is everyone messing with EPA at the moment... I've never heard of anyone doing this before - WOT (wide open throttle) means the MMM is at max and hence 125 won't do anything at all.

If you calibrated your MMM with EPA at 125 then WOT is effectively 100% so again you've done nothing. Setting EPA at below 100% for anything other than training ie kid use is pointless.

It is more ineffecient on the motor and esc so I'd expect less runtime and more heat...

If you want to drive at 60% just hold the trigger at 60%...

Personally It looks like you need a 4S setup to be happy...

jzemaxx · 05.15.2009, 01:02 PM

I plan to try it this weekend and see how it does. Just was wondering. The 3S setup works flawless and have made 20 min main with plenty still left in the batt's (10.9v left in each). Which means that is probably a solid 30 min setup. Now I was thinking the 6S would be lighter and keeping the same rpms would keep amp draw lower with the higher V available. 4S I tried already runtimes were less only 15-17mins max and twin 4's is heavy.

Our track is pretty large so you have to have lots of MAH to make the big mains.

http://www.youtube.com/watch?v=C5xT8jB8v1o

brushlessboy16 · 05.15.2009, 01:56 PM

Just gear down instead of changing EPA and everything.. your setup will run most efficient when the ESC can hit WOT

lincpimp · 05.15.2009, 03:50 PM

I would get a lower kv motor (half of what you run now), and run the packs for 6s 5kmah. You will pick up runtime and also have a cooler motor, and most likely have a little more punch as the packs will not be stressed as hard.

nitrostarter · 05.15.2009, 04:06 PM

So you are trying to go without swapping packs in the mains I'm guessing.

I'd go with linc's lower kv motor suggestion on 6s. Maybe get 2 more of those packs and parallel them and get 6s 10,000mAh....

lincpimp · 05.15.2009, 04:16 PM

Quote:

Originally Posted by nitrostarter

So you are trying to go without swapping packs in the mains I'm guessing.

I'd go with linc's lower kv motor suggestion on 6s. Maybe get 2 more of those packs and parallel them and get 6s 10,000mAh....

Too much weight Spanky! He already said he did not like the weight of a pair of 4s packs in parallel. I guess I got that 36 in reading on the ACT for a reason...

nitrostarter · 05.15.2009, 07:24 PM

Quote:

Originally Posted by lincpimp

Too much weight Spanky! He already said he did not like the weight of a pair of 4s packs in parallel. I guess I got that 36 in reading on the ACT for a reason...

Ok Mr. High score on the ACT test, you have to do this to me on everything post huh?

jzemaxx · 05.15.2009, 04:37 PM

Yeah, the 3S packs 5000mah weigh 386 grams each. A single 6S weighs only 730 grams. My 4S packs are 420 each.

lincpimp · 05.15.2009, 04:42 PM

Quote:

Originally Posted by jzemaxx

Yeah, the 3S packs 5000mah weigh 386 grams each. A single 6S weighs only 730 grams. My 4S packs are 420 each.

What setup are you running with these batts?

jzemaxx · 05.15.2009, 04:43 PM

Quote:

Originally Posted by lincpimp

What setup are you running with these batts?

MMM 2200 on a 2.0 truggy. Works excellent....

lincpimp · 05.15.2009, 05:10 PM

Quote:

Originally Posted by jzemaxx

MMM 2200 on a 2.0 truggy. Works excellent....

Ok, If it works well I would stick to what you have. Running the 2200 motor on 6s will decrease the effecientcy of the motor due to the way high rpms. You could go with an 1100 kv neu 1515 on 6s with the same bearings. I would go to a 1500-1600kv motor for 6s myself...

jzemaxx · 05.15.2009, 05:14 PM

I was looking at the 1515 3.5D and 3D as well.

_paralyzed_ · 05.15.2009, 05:57 PM

the big debate about epa and its use is mostly pertinent to the effects it has on the esc. What temps were the esc at after extended 60% throttle epa? Back to back runs of the same amount of time with a 3s 100% and a 6s 50% would probably tell us what we want to know, which is, what is it doing to the esc?

All the intelligence i've read about it say leave the epa alone once you've calibrated the radio.

I'm happy to read about your experience if you try it