MMM Explodes into FLAMES!

[jpoprock]

Sorry, no video. But here is what I posted in "another forum".

Was driving my Brushless ERevo around over the weekend at a family "camp out". My bro in law was driving around his Losi Ram and I my 3.3 (smoking him), and then my ERBE... which REALLY blew the boys away! I wasn't really doing anything spectacular. Just driving it around grass and asphalt, not fast like speed runs. Just driving it around, popping some wheelies, and landing some skateboard ramp jumps. I didn't feel like I was pushing it AT ALL compared to other times I drive it. After 20min of that, it stopped moving. I peeled the lid back (not the lid pictured fortunately!) to see if maybe a battery connection came loose (which can happen after a jump landing), and before my eyes....POOF! The ESC went up in flames. Literally! FLAMES! I ripped the body off and immediately pulled my $300 lipos out, not wanting them to explode and destroy the entire truck... and was able to get them out. My brother in law blew the ESC fire out. So it's charcoal, and I have NO idea why. Fortunately, Castle will cover it fully under warranty (I presume), but MAN was I bummed out!!!

My batteries are Flightpower 3s 5000mah 30c lipos. My brakes are set at 30% and my punch at 100%. The batteries were fully charged and I had only been driving around for maybe 15min tops. And that includes some starting and stopping to do this and that, turn the veh over if it rolled, etc. I run the Lipos parallel of course. The motor is a Neu 1515 2.5d and I think it's ok. But I couldn't believe my eyes when that thing puffed into flames. It was like magic. I didn't see any smoke, nothing. Just POOF! with instant 4inch flames!!! I was determined to pull those lipos though, cuz I knew the ESC would be covered, but the Lipos? Nope. If the truck had exploded too, would I have gotten another one from Traxxas? Not likely. So, I had to save the batteries and the truck. Fortunately, I escaped with only a blistering burn on my finger, and a very small section of the chassis is melted. But I don't think enough to need to do anything about it. My body (not the one pictured) is fine too. A tad melted, but very minor. It's my basher body anyway.

Took these about three hours before I drove the vehicle. Nothing changed....











The horror:







The batteries: The only thing that was toast was the shrink wrap had melted.





My voltmeter, which may not mean much... had them at 11.47 I think. Both packs. So, I'm pretty sure that they aren't toast. They aren't puffed at all, nor are they soft. I'm going to charge one and closely monitor the charge, and will reshrink them if all goes well!

This could have been MUCH worse, but still....<shudder>

P.S. - The Moabs? Yes.... I know!

[Bondonutz]

Hmmm, Thats really strange ?
I'm sorry I have nothing to add as to why you had the meltdown but you have my condolences for your loss.

[needforspeed]

I have had two mmm fires and i hate the smell !!! its the worst chemical smell ever. Your bringing back bad memories........ sniff , sniff

[Kcaz25]

Moabs are almost never good for a practical BL high torque beater. They look saweet though.

My condolenceses

[BL_RV0]

The setup should be run on at least 4s, but 5s would be better to yank around those big tires. I'll bet the ESC had enough and bit the dust. You really should look into a 5s setup...

[suicideneil]

Nasty. Motor and voltage choice is fine, only question is what gearing and esc settings were you running?

Seems like a random failure though rather than bad setup and/or being pushed too hard...

[suicideneil]

Originally Posted by BL_RV0

The setup should be run on at least 4s, but 5s would be better to yank around those big tires. I'll bet the ESC had enough and bit the dust. You really should look into a 5s setup...

3s + 3s = 6s, he was running the batts in series I'd wager.

[BL_RV0]

Originally Posted by suicideneil

Nasty. Motor and voltage choice is fine, only question is what gearing and esc settings were you running?

Seems like a random failure though rather than bad setup and/or being pushed too hard...

He was running 3s....

[suicideneil]

Really? Says 6s in his sig, no mention in the opening post- unless he said 3s in 'the other forum'...

In which case = bad setup, unless it was geared for no more than ~20mph on that voltage with that motor.

[Arct1k]

You can see in the pic it is wired for 6s... Schultz would say too long battery leads...

PS That is not as far gone as my MM's went - I sent back the few burnt fets I could find...

[Bondonutz]

Originally Posted by BL_RV0

He was running 3s....

I re-read the post and will quote;
"I run the Lipos parallel of course."
??????????????????????????????????????????????
Unless he's mistaken and ment series ?

[BL_RV0]

Originally Posted by jpoprock

My batteries are Flightpower 3s 5000mah 30c lipos. I run the Lipos parallel of course.

.........

[What's_nitro?]

According to this pic he was running 6s:



Notice the batteries are in series. That could be the problem. Maybe hes was overgeared for 6s 'cause the thought he was running on 3s?


Sorry about your MMM, CC will take care of ya.

[Bondonutz]

[QUOTE=What's_nitro?;302197]According to this pic he was running 6s:



Notice the batteries are in series.

I didn't see this, good catch. The meltdown is still unexplainable till we know more about gearing and settings. Still could easly be a freak of nature.

[fastbaja5b]

After reading the article from MGM regarding volt spikes and braking, this makes sense....

The MMM may be rated for 6s, but I wouldn't do anything silly like use your brakes in that set up.

The batteries look adequate but what were you geared at?

Hopefully Castle can sort this out for you and address the rising death count of MMM's on 6s Lipo