Found the perfect LiPo for MMM Slash!

[zephyrwingz03]

THIS IS IT

6S 20C 5000mah LiPo for only $60

[Jason_garrison]

I would probably run a lipo with a higher C rating than 20C. Its better for the battery longevity to have a more than enough amp output than be right on the edge of being ok.

[zephyrwingz03]

Are you saying that all 20C rated LiPos out there are pretty much useless then?

[J-DUB]

Are you saying that all 20C rated LiPos out there are pretty much useless then?

unless you are running them in a small truck and or a plane or something.

[ksb51rl]

Sooo, my ERBE running pair of SPC 2S/20C/8000mAh batteries in series is running useless batteries?
J_g is right, but C-rating is not the only factor determining amp output. I would guess that a decent 6S/20C/5000mAh battery would be fine to power a MMM Slash. Whether the drivetrain could take that is entirely another story. I haven't looked at any exploded views or part numbers to make a guess at whether it's supposed to handle 6S.

[brushlessbandit]

^that was owned

at 6s i don't think you could notice a big difference in 20c vs. 30c+ unless you are doing reeaaaaallllllyyyyy high speed runs like 80+mph i wouldn't care, just another excuse to pull the trigger harder "well... since my battery was only 20c i thought it would go slower than it did...", "O well, upgrade time!"


and anyways, are you doubting that a traxxas vehicle can effectively run off of a 20c battery?

[8ight-e]

Unless you are doing speed runs a 6s setup is rediculous for this truck.. think of the 800grams w/ the battery, the additional weight of the MMM those stock shocks are bad w/ stock weight let alone that much extra iMO. Big Bore upgrade or better to handle even the smallest jumps. PS I'd keep the slipper in w/ a 6s setup and run it loose if you want the drive train to last for any amount of time.

[outkast187]

Id rather run a 1500mah nicd than a 6s in this truck.

[rag6]

Ksb, isnt the c rating directly related to the mah of the battery? Does the cell count affect this in series? What I am unsure of is would that 6s 5000 mah 20c pump the same amps as a 2s 5000 mah 20c (both 100 amps)?

[danielhr77]

I've been running two Venom 3S 20C 5000mAh packs for over a year now in my Rustler VXL, Stampede VXL and Bandit VXL and I don't have any issues at all... 20C is enough for this kind of truck... Also, take into account that 6S won't work on the stock truck with the Velineon...

[Hoodala]

Since you are planning to run 6s I have to assume you are upgrading to an mmm or rx8. Castle recommends 25c as a minimum for the MMM, any lower and you are under amping the motor. Under amping can cause just as many problems as heat and over amping a motor.

Another thing you might want to think about is going with 2 3s batteries instead of 1 6s. There are advantages to having the extra battery just in case, and if you ever take it to the track you don't want to be running 6s it is way overkill.

[brushlessbandit]

Ksb, isnt the c rating directly related to the mah of the battery? Does the cell count affect this in series? What I am unsure of is would that 6s 5000 mah 20c pump the same amps as a 2s 5000 mah 20c (both 100 amps)?

they will both give the same amps, but you would find a longer runtime with the 6s because you are npt pulling the trigger as hard for the same speed, and anywhere but BIG, BIG, streets no one needs to use the power of 6s.

[8ight-e]

they will both give the same amps, but you would find a longer runtime with the 6s because you are npt pulling the trigger as hard for the same speed, and anywhere but BIG, BIG, streets no one needs to use the power of 6s.

I get what your trying to say, but it's got nothing to do w/ the trigger..

For example to hit 50mph you need 2220watts (fake number)

22.2v * 100amps = 2220watts

to get the same speed with 4s

14.8v * 150amps = 2220watts

Gearing will obviously be different and the throttle control will be the exact same, as well as speed but with less amps being drawn the higher voltage system will run more effecient and be less demanding.

It's just math; voltage * amps = watts

Funny thing is if you just add voltage and increase top speed and don't gear down you gain nothing and the system maybe faster, but burns up and draws just as much, maybe more! Also if you are never at WOT it will also be even less effecient so you can't simply turn down the throttle w/o a gearing change. The ESC needs to be opened up for max effeciency.

[brushlessbandit]

thats what i trying to say, when you dont pull as hard on the throttle you dont draw as many amps. with a 6s you press throttle and draw less amps than 3s or 4s



thank you for sorting out any confusion

[ksb51rl]

Ksb, isnt the c rating directly related to the mah of the battery? It is a coefficient (or multiplier.) "20C" simply means that the battery's maximum constant discharge current is 20 times the amp-hour rating.
Does the cell count affect this in series? What I am unsure of is would that 6s 5000 mah 20c pump the same amps as a 2s 5000 mah 20c (both 100 amps)?

8ight-e has explained it. I would have used the maximum volts/cell rating of the LiPos and not the nominal volts/cell, but that does not change the point of his post. Either way, it's the same amps, but the 6S will provide 3x the wattage.
Amperage = current.
Wattage = power.
Voltage = potential (or push).

[annonymous]

a 20C 5000 (regaurdless of cell number) will put out something around (20 X 5.000 (5000 mAh is 5 A)) 100 A discharge - - -that might be a tad low for something like a MMM, even though it is a lighter truck, but will still work well

i would say to try to find a 4s 30c 5000 or so for this truck, because IMO 6s is ALWAYS too much, especially in a small truck like this.......

You will prob. only ever need 6s in a top speed run based truck, which seems like is not exactly the purpose of this truck

[outkast187]

you dont need a 30c, even with the monster. Unless you are geared to the moon for some odd reason, and running it to death like that...its totally not nessisary. I run a 8th scale for 20 minute races on 20c packs, and its just as fast as my 30c or 40c packs. Ive done it, I know what to look for, and 20c works. I run it on a mamba monster 2650 in the buggy and a 2200 on a SC8. Both of which pull alot more current than a slash 4x4 will.

[8ight-e]

6s is fine if you get a 1300kv motor... so choose your parts wisely! At 6s it will demand less amps at the given speed so you could have a battery capable of less, but you still need to factor in price and run time.

Monster geared for same MPH these batts will allow ~same run time
22.2v 3300mAH
15.8v 3960mAH
14.8v 4950mAH

Velineon geared for same MPH these batts will allow ~same run time
11.1v 3333mAH
7.4v 5000mAH

EDIT: Don't directly compare the monster vs velineon here as the run time on a monster w/ 4s lipo vs velineon w/ 2s lipo WILL be different depending on your variables, just compare those figures w/ each other on the same ESC for ~ same run times. 4s+ lipo on a Velineon wouldn't last you long.. too high of RPMs.

In reality these trucks can race on any track stock w/ a 2s 5k lipo.. 3s for speed runs or a little bashing zip. Upgraded systems will not yeild faster lap times on a off-road track but I guess if for some reason you run your 4x4 on a touring car track or drag race it you could spank up the speed. Though there are much better vehicles for this... anyway Traxxas is smart showing a picture of the slash 4x4 w/ a mamba monster upgrade, people will have the upgrades purchased before they ever run the stock config and realize the stock config can be too much all by itself!! LOL outstanding 'merchandising' iMO

[outkast187]

agreed 100%.

[annonymous]

6s is fine if you get a 1300kv motor... so choose your parts wisely! At 6s it will demand less amps at the given speed so you could have a battery capable of less, but you still need to factor in price and run time.

Monster geared for same MPH these batts will allow ~same run time
22.2v 3300mAH
15.8v 3960mAH
14.8v 4950mAH

Velineon geared for same MPH these batts will allow ~same run time
11.1v 3333mAH
7.4v 5000mAH

EDIT: Don't directly compare the monster vs velineon here as the run time on a monster w/ 4s lipo vs velineon w/ 2s lipo WILL be different depending on your variables, just compare those figures w/ each other on the same ESC for ~ same run times. 4s+ lipo on a Velineon wouldn't last you long.. too high of RPMs.

In reality these trucks can race on any track stock w/ a 2s 5k lipo.. 3s for speed runs or a little bashing zip. Upgraded systems will not yeild faster lap times on a off-road track but I guess if for some reason you run your 4x4 on a touring car track or drag race it you could spank up the speed. Though there are much better vehicles for this... anyway Traxxas is smart showing a picture of the slash 4x4 w/ a mamba monster upgrade, people will have the upgrades purchased before they ever run the stock config and realize the stock configuration can be too much all by itself!! LOL outstanding 'merchandising' IMO

Also Agreed - -very, very true

I guess the appeal in a huge system originally proposed for a 1/8 or large 1/10 monster truck in something as small as this is the insane stump-pulling/lawn tearing/earth moving abilities......

on my above post i meant 25c, but it for some reason came out 30..... - - - - you could get this same battery for $60 or under also......5c more and a more SANE system for the same price or less!

You could get the ***** *********x 5000's 2S (20 or 30C) and get two and run them with a series connector............more flexible for other possible "investments" $20 each for soft case(20C) and $30 for hard(30C) -........ my $0.02

[rag6]

8 and ksb, Thanks for the understandable info. That cleared everything up.

[filmmaker]

6s is fine if you get a 1300kv motor... so choose your parts wisely! At 6s it will demand less amps at the given speed so you could have a battery capable of less, but you still need to factor in price and run time.

Monster geared for same MPH these batts will allow ~same run time
22.2v 3300mAH
15.8v 3960mAH
14.8v 4950mAH

Velineon geared for same MPH these batts will allow ~same run time
11.1v 3333mAH
7.4v 5000mAH

EDIT: Don't directly compare the monster vs velineon here as the run time on a monster w/ 4s lipo vs velineon w/ 2s lipo WILL be different depending on your variables, just compare those figures w/ each other on the same ESC for ~ same run times. 4s+ lipo on a Velineon wouldn't last you long.. too high of RPMs.

1300kv on 6s?
you can run more kv on 6s, thats only 29,000rpm on 6s..
and 6s on the same motor as running 3s can pull more amps on 6s, you need to go down in kv to pull less amps of the same size can
just going up on cells does not mean you will pull less amps
I assume these numbers are from a calc and not real world?
things get a little different once mounted and runing in a actual truck
also the VXL motor will work nutso on 4s and last

[filmmaker]

THIS IS IT

6S 20C 5000mah LiPo for only $60

that battery will work great in this light of a truck..
but the speed and power of a MMM on 6s... LOOK OUT !!

[annonymous]

1300kv on 6s?
you can run more kv on 6s, thats only 29,000rpm on 6s..

i think that is sufficient rpm considering on a 1:1 final drive the truck would in theory (if my math is right?) would do 170 MPH - - - -sooo gear it DOWN!!!!

a electronics setup that is somewhere around equal, like 1300 Kv on 6s vs. 2100 Kv on 4s (or whatever the ratio is), should be close in speed and power, but will give less wear and tear to everything in your truck - and its cheaper to buy lower voltage batteries

[brushlessbandit]

or..... you could get a 1300kv motor and 6s and instead of letting that stupidly large amount of torque go to waste- gear up! 32/32 should work or any 2 same numbers

[filmmaker]

i think that is sufficient rpm considering on a 1:1 final drive the truck would in theory (if my math is right?) would do 170 MPH - - - -sooo gear it DOWN!!!!

a electronics setup that is somewhere around equal, like 1300 Kv on 6s vs. 2100 Kv on 4s (or whatever the ratio is), should be close in speed and power, but will give less wear and tear to everything in your truck - and its cheaper to buy lower voltage batteries

Not sure where you get your math
the stock VXL on 2s would be 25,900rpm, so by your math the stock setup is good for 151.8mph
sooo on 3s that would be 227.7mph! say what?

[filmmaker]

I think a great setup is the new 10th pro esc on 6s with a Blackjack motor or SV27 motor
they would not pull to many amps so runtime would be good and produce alot of power at the same time
I've gotten into FE boats big time and have spent alot money on them or this is what I would love to try

[annonymous]

Not sure where you get your math
the stock VXL on 2s would be 25,900rpm, so by your math the stock setup is good for 151.8mph
sooo on 3s that would be 227.7mph! say what?

in a truck with a final drive of 1:1 those speeds would be appropriate with around six inch circumference tires and accounting for parasitic loss and such......, but the 4x4 is more likely 4:1 or so.......that 227 becomes around 50 MPH

[brushlessbandit]

plus drag, 40mph like traxxas CLEARLY stated.
I am 100% sure traxxas would be advertising the heck out of it if it went 227mph!

[annonymous]

plus drag, 40mph like traxxas CLEARLY stated.
I am 100% sure traxxas would be advertising the heck out of it if it went 227mph!

only if the FAA didn't ban it first for entering federal airspace!

But, to give this thread back to zephyrwing, i would say 6s is excessive and will wear electronics out prematurely, something that could be more easily avoided at something like 4s.......IMO