Oh #%@!! What did I do to my SMC Lipos?

higher voltage with appropriate gearing and motor selection will give the optimum setup....only reason im running 4s on my NEU maxx is i am using a MM and 4s is already pushing it a bit.


quality differnece in $220 maxcraps (smc may be like maxamps..) and $180 neu packs with enerland 5000mah cells......
http://www.youtube.com/watch?v=fp94K0TGfTY

[BrianG]

Maybe this was mentioned somewhere in this thread, but it looks like both packs puffed. Maybe it's just the angle of the pic (first one), but the one on the left looks puffed as well, just not as badly.

On a side note, I'm not really sure I like hard-case packs. Sure, they protect the lipos physically, but if they are tied down well enough, that shouldn't be a concern. My beef is that having packs enclosed doesn't exactly promote good airflow. And if they get too hot, they can puff. Maybe they were ok amp-wise, but since there was no cooling, they puffed anyway?

Originally Posted by BrianG

Maybe this was mentioned somewhere in this thread, but it looks like both packs puffed. Maybe it's just the angle of the pic (first one), but the one on the left looks puffed as well, just not as badly.

On a side note, I'm not really sure I like hard-case packs. Sure, they protect the lipos physically, but if they are tied down well enough, that shouldn't be a concern. My beef is that having packs enclosed doesn't exactly promote good airflow. And if they get too hot, they can puff. Maybe they were ok amp-wise, but since there was no cooling, they puffed anyway?

Oh, they both puffed, trust me

Originally Posted by Freezebyte

Oh, they both puffed, trust me

....id call em and see if they replace them... but remember to change gearing when taking the grass on. but in the end sounds to me the packs are bad.

sorry for your troubles and trust me i hear your frustration...but once it gets sorted out, its hella fun

I"m so upset I just wanna throw up. First my HDD fails on the 4th with all my data that I didn't back up, then my power supply croaks on my gaming rig last week, now this week my 50" Sony LCD screen has screen imperfection and NOW I can't drive my Flux anymore due to this Lipo shit storm.

I'm glad i'm leaving on vacation in a few days in the mountains, I hate everything tech wise right now.

[zeropointbug]

I'm sorry man, you are having some bad luck lately... more like against all odds bad luck. I feel for ya.

Okay, if you do not need the 'most powerful' battery pack out there, then you should consider getting an A123 pack for your Flux, I am think a 6s2p pack would be a very good voltage for that motor. Hell man, I will even get the cells and build the packs for you!

You will be able to through EVERYTHING you could get the Flux to muster at the A123 pack and it would not give up on you, they are virtually indestructible, they last and last, and do not loose any performance over their entire life time.

Let us know what you are going to do.

[fastbaja5b]

Unless people have missed the umpteen eagletree graphs I have posted, nothing wrong with his set up at all, stock set up, Savage Flux 4s Lipo, max amp spike is 120 Amps that I have seen on my set up which is pretty much identical. I run 5000mah 30C packs and mine don't puff. Instead of helping we have a bunch of know alls preaching higher voltage, get better packs etc etc yet when he was toying with what packs to buy, people with the same attitude were asserting SMC is a "good brand"

No wonder he feels disenchanted with the hobby right now.

My guess is when the lipos first puffed a bit as you stated some damage may have been done, and it's cascaded from there, as my testing has shown, a 3.2v/cell lipo cut off on the MMM is insufficient and doesn't stop the packs dropping below that under amp load, just another shortfall of a problem plagued ESC.

Query it with SMC, up your LVC to 3.5v/cell and remember that there are some people who just like to bombard you with you should and you shouldn't do's on forums, human nature.

Originally Posted by fastbaja5b

Unless people have missed the umpteen eagletree graphs I have posted, nothing wrong with his set up at all, stock set up, Savage Flux 4s Lipo, max amp spike is 120 Amps that I have seen on my set up which is pretty much identical. I run 5000mah 30C packs and mine don't puff. Instead of helping we have a bunch of know alls preaching higher voltage, get better packs etc etc yet when he was toying with what packs to buy, people with the same attitude were asserting SMC is a "good brand"

No wonder he feels disenchanted with the hobby right now.

My guess is when the lipos first puffed a bit as you stated some damage may have been done, and it's cascaded from there, as my testing has shown, a 3.2v/cell lipo cut off on the MMM is insufficient and doesn't stop the packs dropping below that under amp load, just another shortfall of a problem plagued ESC.

Query it with SMC, up your LVC to 3.5v/cell and remember that there are some people who just like to bombard you with you should and you shouldn't do's on forums, human nature.

That pretty much sums up my feelings.

[zeropointbug]

Both packs failed? WTF were you doing to them? Were you shorting the leads out? lol

I find that very odd that they would fail, even when you only have a 4s2p pack in an E-Savage.

I have been running both a 7s1p and a 7s2p pack in my trucks for the last 3 years and have had none fail on me, the 7s1p pack still goes strong like day one and I have bagged the snot out of it. I now run Hyperion G3 35C packs, these things are truly outrageous... going from the A123 packs to my other 25C Enerland packs was a huge difference, then the G3's are another big jump in craziness again.

Originally Posted by zeropointbug

Both packs failed? WTF were you doing to them? Were you shorting the leads out? lol

You tell me and no, I was not doing that.

[zeropointbug]

Originally Posted by Freezebyte

You tell me and no, I was not fucking doing that.

I was referring to FastBaja5B.

[What's_nitro?]

Originally Posted by Freezebyte

You tell me and no, I was not frakking doing that.

Ermmm, he was talking to fastbaja5b.

[zeropointbug]

Originally Posted by What's_nitro?

Ermmm, he was talking to fastbaja5b.

He quotes me, yet was referring to B5B... that's logical.

And Linc put the effort in the make a very good post... listen to what he is saying.

And he is also correct, no one on this forum would 'recommend' SMC packs, we never have, unless you bought them already and then asked if they were okay, and someone may have said "ya, they are okay".... they are unproven, and unknown cells.

If you want reliability and still have plenty of power, go for an A123 pack, I can personally testify to the robustness of these things, I have used them for 3 years now; overcharging them, over discharging them many times, taken them over the rated limits (seen over 60C bursts on my 7s1p pack), and they come back for more.

If you want the best performance and quality in a pack, then go for Hyperion G3's, FP EON X30's, or Neu packs.... or if you are tired of spending money on packs, go for Zippy/Turnigy packs, dirt cheap and they perform, and have a good track record thus far.

But before you decide what pack you want, obviously check with SMC what they can do for you. Maybe tell them your situation.

[lincpimp]

Originally Posted by fastbaja5b

Unless people have missed the umpteen eagletree graphs I have posted, nothing wrong with his set up at all, stock set up, Savage Flux 4s Lipo, max amp spike is 120 Amps that I have seen on my set up which is pretty much identical. I run 5000mah 30C packs and mine don't puff. Instead of helping we have a bunch of know alls preaching higher voltage, get better packs etc etc yet when he was toying with what packs to buy, people with the same attitude were asserting SMC is a "good brand"

No wonder he feels disenchanted with the hobby right now.

My guess is when the lipos first puffed a bit as you stated some damage may have been done, and it's cascaded from there, as my testing has shown, a 3.2v/cell lipo cut off on the MMM is insufficient and doesn't stop the packs dropping below that under amp load, just another shortfall of a problem plagued ESC.

Query it with SMC, up your LVC to 3.5v/cell and remember that there are some people who just like to bombard you with you should and you shouldn't do's on forums, human nature.

Kind of like you... That last statement does not really hold much water dude.

I for one would never recommend smc packs, and have not. General consensus is that an enerland cell pack will have the least mfg defects and early deaths. So they are the best bet right now due to them being well proven. I have handles countless puffed lipos, and have seen the least amount of defective cells come from enerland.

The packs puffed for some reason, either being overdrawn, or the voltage pulled too low and then pulled very hard. I think they have been marginal the whole time he has been running them, and they finally gave it up.

I have run countless motors with the MMM in various vehicles and set my lvc to 3.2v per cell. No issues at all, not one, ever. I even ran a completely dead fp 4500 30c 6s lipo (by accident) in the muggy for a few minutes and wondered why the damn thing was stuttering so bad, figured the lipo was cold. It was the lvc kicking in, but the pack was good enough to provide enough juice to pop the voltage back up to rearm the MMM. Put 4700mah back in that pack, no puffing, and no loss of performance since. The MMM lvc works fine, if your cells can't handle the load and dip below the lvc while you are running you have bigger problem, like your cells are not up to the task. Plus the eagletree sampling rate is pretty high, and I am sure the MMM has some amount of flexibility in its measuring.

Plus the 3v per cell thing has a fair amount of saftery window, you can discharge a lipo down to 2v, and unless it was a very high load the cell will charge up fine.

Bottom line is that your graphs may say that he only needs 120 amps, but who is to say the smc lipo ratings are close at all. They puffed, and it does not seem like user error or the fault of the MMM. The tall grass loaded the motor, it asked for more and the lipos failed, not the first time this has happened.

If you are hitting the lvc before the pack is almost empty, then you need a better lipo with a higher rating, no way around that logic.

[rawfuls]

Not to kick the cow more, but, I've heard that the Badlands in average, even very short grass can rip pieces out of the ground, seeds, etc.

Now, if tires are this grippy, couldn't this cause more... strain on the drivetrain? Since the badlands are getting so much grip into the soil, it's almost like it's binding.

Or am I just being stupid again?"

Freezebyte, it does sound like you're getting the evil fairy of technology.... Hopefully things will be better... They should be.