What happened?

[ambrodyo]

So I took my ER with MMM out for a run the other day since we finally got some sun, and after a short bashing period took it in and put it away for the evening. Next day, I charge my batteries and take it outside for another bashing run, and when I turn on the switch, I notice some black smoke coming out of the ESC and could hear a stuttering/grinding noise coming from the ESC. I shut it off, opened the ESC to see if there was any damage or moisture from the previous run, but it looked nice and clean and dry. I reconnected the batteries and turned the switch back on. The usual chirps from the ESC sounded groggy and the fan came on and stayed on, followed by a huge puff of black smoke, sparks, and finally ending the fireworks show with one of the leads of the battery flying off the high flow connector. I looked at the battery packs (7-cell 4600 Losi NiMH) and noticed that the shrink wrap around the cells had melted away where the wire was placed across the battery cells. I'm not sure what happened, and hope I'm not out $300. Any ideas would be appreciated. I'm fairly new at this and not 100% sure what I'm doing and dont want to make things any worse.

Thanks--

[WhoDat]

So I took my ER with MMM out for a run the other day since we finally got some sun, and after a short bashing period took it in and put it away for the evening. Next day, I charge my batteries and take it outside for another bashing run, and when I turn on the switch, I notice some black smoke coming out of the ESC and could hear a stuttering/grinding noise coming from the ESC. I shut it off, opened the ESC to see if there was any damage or moisture from the previous run, but it looked nice and clean and dry. I reconnected the batteries and turned the switch back on. The usual chirps from the ESC sounded groggy and the fan came on and stayed on, followed by a huge puff of black smoke, sparks, and finally ending the fireworks show with one of the leads of the battery flying off the high flow connector. I looked at the battery packs (7-cell 4600 Losi NiMH) and noticed that the shrink wrap around the cells had melted away where the wire was placed across the battery cells. I'm not sure what happened, and hope I'm not out $300. Any ideas would be appreciated. I'm fairly new at this and not 100% sure what I'm doing and dont want to make things any worse.

Thanks--

Looks like your mmm burnt. A few reasons why this may have happened. Call catsle and you can send it in to get it checked. If it messed up do to product failure they will send you a new one. Best thing I can suggest. Good luck and hope you get it working soon.;)

[mkrusedc]

Opening the MMM esc voids the warranty....

[brushlessman]

yes but they will most likely not say anything about it

[Seattle Slew]

Send it in, about 1 in 10 has failed.

[sellinchevs]

Send it in, about 1 in 10 has failed.
Not to start another battery bash session or anything but..........

I might know somebody who knows somebody pretty high up at Castle Creations. These MMM systems are really meant to be run on Lipo batteries, plain and simple. Even super high quality NIMH's don't do it justice, and you don't want to get him started on the cheap quality LIPO's. Food for thought, almost straight from the camels mouth.

[littlejohn]

Send it in, about 1 in 10 has failed.

;) I would like to see where you got this statistic from??

[sellinchevs]

Send it in, about 1 in 10 has failed.
I don't know the exact failure rate, but I'm pretty sure a majority are from undergearing and lousy batteries. Get a good truck, get good cells, get performance, get longevity...............

[EMAXX ab USER]

My MMM did almost the exact same thing. first run it was great. Second run it died, smoked, groggy startup noise, smoke again and anytime a battery is hooked up thereafter. POS thing anyway. Sent it away. Still waiting for return. that was three weeks ago. not fun. I think the rate of failure is more like 6 out of 10.

[sellinchevs]

My MMM did almost the exact same thing. first run it was great. Second run it died, smoked, groggy startup noise, smoke again and anytime a battery is hooked up thereafter. POS thing anyway. Sent it away. Still waiting for return. that was three weeks ago. not fun. I think the rate of failure is more like 6 out of 10.
No crying aloud............stuff happens with anything mechanical or electrical you all know that.... nothing is perfect or lays claims to be, but there is usually more to the story

[Revo¹]

According to Patrick (owner of CC), you should not run the MMM with NiMH cells, and if the designer of the thing says that, I am going to follow it.

That doesn't mean that the NiMHs are what caused the problem, but it is highly likely that they did.

Also, 1 in 10 MMMs fail? That is so far from the truth its rediculous...IIRC, Patrick said that it was like 1 in every 1000 have failed, with 75% of those failures being user error, 20% battery-caused failures, and 5% actual product failure...and that was the older versions, the new versions having an even lower failure rate. The post is over on RCM, and is like 40 pages long.

[moneypitrevo]

I spoke with Patrick the other day just got mine back also. They discourage all cheap lipos. NIMH they discourage completely they just do not have the amperage this system needs. As for cheap lipos I am not even going there this will turn into a battle on this forum. Neu Batteries are very good though although not cheap.
They may or may not warranty your ESC depending on if you tell them you were running NIMH the manual says not to.

[Jason_garrison]

You wouldnt put 87 octane fuel in a top fuel dragster. Smiliar principle applies here, if you want to use one of the most powerful brushless systems on the market why use cheap batteries in it?

Use proper batteries, keep it running cool, gear it properly, and you will hardly ever have a failure.

I run my e-revo geared 18/68 and nothing ever gets over 130 degrees, the fan hardly ever comes on the esc. The system is rock solid and 6 out of 10 failure rate is laughable.

You have to remember that the ones who have had an issue (usually their own fault) are the ones who speak the loudest, the ones who are happy with theirs are out running them and not complaining.

But a better point, do you really think that Traxxas and HPI would use a system with a 60% failure rate on their most expensive products?

[asheck]

What, does it appear the message is getting out, :) please read sig
Neu Batteries are very good though although not cheap. I think they have good value. I paid 195 with shipping for my 2 3900 4s, that equates to 97.50 for a 7800 25c 2s.

[mkrusedc]

My version one MMM is still working!! :wub: I only feed it TrakPower and Neu batteries.:p :lol:

[asheck]

What was your gearing? Did you notice any signs of problems with the batteries while charging?