I think running 6s is a bit excessive personally. With 4s there is more power is on tap that can be used when bashing anyway ?
I have 5 M.M.M. and a couple have had hundreds of runs using 4s with zero issues, I have several friends whom like the 5s & 6s with their trucks and these guys have problems occasionally. Usually heat issues and other minor stuff,no smoke letting (yet).
When we are out running together even though they have more power on tap they can't use it because of where we run,surface,obstacles ETC you just don't get a chance to wring it out.
The Castle ESC is a awesome affordable controller but I beleive a lot of extra care and consideration to the set up has to be made to run reliably with 6s to do it with no heat issues and do it safely. Then theres always the luck of the draw that some of these guys who run 6s might have a defective ESC, shit happens.

From what I've read about some guys experiences with their problems Tekin was right on it resolving the issues. Same great customer service as Castle

I agree with Bondo. 6S really isnt required for a 45mph or below setup. I was just hoping to milk cooler temps with my 6S setups, but maybe it just doesnt matter. 4S will get me the speeds and torque I need given the MMM current handling abilities. On 4S the controller is going to get warmer than what I would like so I figured a 6S setup would be better for cooler running electronics. 5S has been the sweet spot for me for the 2200 combo in terms of temps, power and reliability. Even on 4S there is enough power on tap to shred as many RC parts as you can buy.

One thing I forgot to mention, In most of my trucks I have 6.5" or larger tires and geared for 40-45mph and live in Fl. My ESC fans very rarely come on with 4s.

A rather broad statement with nothing really backing it up. In a revo, yes 4s can be fine, however in heavier trucks like an LST2 it makes a world of difference. The biggest advantage to higher voltages is the ability to use lower KV motors and the ability to keep the same performance while lower amp loads.

6s in itself is fine, but people should not be using the heaviest wheel/tire combo then gearing for 60+. Then they wonder why the setup blows. 99% of the failures I see on here on 6s are setup related.

Hence the "personally". In my LST2's I run 4s with no probs,my buds who run 5s & 6s in there LST2's have problems. It's just a general statement based on my experiences. Not rules or guide lines that anyone has to follow ?

I do agree with your 6s setup reference

Please don't rip me for posting this thread from the TRX forum. But I thought it was worth noting.

http://monster.traxxas.com/showpost....2&postcount=44

Doesn't seem to me his setup was all that bad at all. But it seems we may not know the whole story. I dunno.

Well... maybe I'll pick up some 2s packs, or maybe stick with 3s and not worry about frying the ESC providing I'm geared to run those big tires, and about 40mph tops. That's plenty fast for what I do. The ESC shouldn't fry on 6s alone. It's got to be combo of things. In my case, I fully realize now that I was overgeared and hadn't taken that into consideration when mounting up the tires. I was just so excited to run them, that I spaced that little detail.

I really don't think people fully understand the impact tire/wheel combos have on their systems. It's not just dead weight which is one thing, it's rotational mass which has a much greater effect pound for pound in regards to stress than virtually anything else. If you are going to do speed runs (in a monster truck anything above 50) then you need to try and get the lightest tire wheel combo possible. It's not just the acceleration but the braking which greatly affects your system. Even HPI states in the Flux manual to use phaltlines when doing high speed runs.

I would also note that a thorough inspection be done of your vehicle after each run to check for binding and for any items the could be lodged in the drive train. I know for a fact both the HPI and TRX manuals state do this on all their RTR's.

As for the TRX forums, I gave up posting there. People just whine and moan when you explain to them there are limits on these systems.

I have been running 6s succesfully with a V2 MMM for a year now in my E-Revo, E-maxx 3905 and LST2 conversion.

yep, another one here. Reading all these stories I kept thinking of how to attribute it to user error, till mine did it today.

Brand new MMM, ran about 20min in my revo geared very conservatively. Went to plug in my battery and it made a much bigger spark than normal. melted one of the metal connectors and some of the solder in the battery packs (breaking the circuit).

I plugged it in on the bench with 2s A123, and it armed fine, made tones etc. Then I plugged in 6s lipo - big spark and a flame (about the size of a cigarette lighter flame) out from the where the neg battery wire goes in. Unplug the battery, the flame goes out. Plug in 3s lipo - arms fine, plays tones and the right lights etc, but I can see all sparks and stuff inside next to that neg battery lead, and something glowing. It still seemed to work, I don't really wanna push my luck though so I've boxed it ready to ship out asap.

Sounds like it could be a fet shorting or something thats causing this - weird that it did it just on arming, and even after the flames, it still seemed to be working.

^^ that is some good info and testing:yes:
could prove valuable to the castle staff, maby put it in the MMM failure sticky at the top of the forum?

Mamba Monster flammage
 

This will explain it all....
http://www.rc-monster.com/forum/showthread.php?t=21973

I wish people would quit posting it, that doesn't explain ANYTHING. All it does is show that you get voltage spikes under braking, not how an FET burns out when the ESC is arming.

This just looks like a faulty FET, nothing more. Perhaps a better FET supplier is required?

Yeah... I reckon its the same as what happened to muted, plug in, arm, flame.

Theyve got some fancy new secret FETs for the MM pro, here's hoping they upgrade the FETs on the Monster... I doubt they wont, its probably the main reason they sourced the new fancy ones in the first place.