New warning insert in MMM box: "DO THE MATH!"
 

My friend got his replacement MMM back from CC last week and told me that there was a new piece of paper inside the box. I have attached it for you here.

http://i143.photobucket.com/albums/r...po_Warning.jpg

Essentially, CC is now saying "We aren't going to name names, but don't use cheap lipos or bad things can be expected to happen!". Which is something we have known all along. My question is about their minimum recommendation of 4000mah 20C cells. If they are stating that the MMM can sometimes demand 100 amps in peaks and that you should always stay at 80A Continuous or LOWER, why is it that everyone seems to always recommend 25-30C packs? If I'm supposed to try and stay at 80 or lower, then my 5000mah 25C Flightpower packs are overpowered according to this graph right?
5A x 25C =125 x 80% = 100. I guess I'm just confused.

It makes me wonder if they think the reason so many MMM's are failing are because of cheap batteries or overpowered batteries? All I know, is that once I get my MMM back, which should be soon, and get my Neu either fixed or replaced, I'm going to continue running 6s, but I'm gearing way down. I'll probably pickup a couple 2s packs and run them as 4s too.

There are tons of people out there running the MMM system with no problems. The ones that have, it's hard to say just why it happened I guess.

What this means it that now any users of MaxAmps packs will be more confused than ever! Since MaxAmps only specifies a surge rating now, users will have no logical way to do the math on the Castle insert.

How can anyone know how much current they're pulling?

I am with CC though. I do not see how it makes sense to go with the surge rating. I would also think if using cheaper cells that giving yourself a buffer would be a given as well.

They aren't saying to stay at 80 amps or lower they are saying that you need batteries that are capable of more than 80amps. there really is no such thing as an overpowered battery, as long as it's less than 6s for the monster. If you could fit 6s 6000mah 40C that's great, capable of 240amps! 6000mah 10C = not good at only 60amps

Eagle tree!

I guess I'm still not getting it. If they are saying you need batteries that are capable of more than 80 amps, why did they print "We suggest you never run the system at more than 80% of the max continuous rating."???

And their formula for the 5000mah 20C cells is right at 80%. Then they go on to say (as if you can't read! HA!), that they suggest a minimum of 4000mah 20C packs.

So, they say "never run at MORE than 80% of the max continuous rating" and suggest that the MMM can hit 100 amp peaks. Right? So if my Flightpower 5000 25C cells which according to their formula put out 100 amps max continuous, and they say "don't run the system at more than 80%", how can higher be better?

I mean, this is what I've assumed all along.. that the more on tap the better, but it seems to contradict what they are saying. It's almost like that thing they wrote up is written incorrectly. No?

of your batts, not the controller... to account for bs lipo claims I'm sure

The system will draw what the system is setup to draw, regardless of what battery you use. If you are geared to draw 100amps, that is what you will draw. Now if the battery cannot handle 100 amps you will have battery and esc issues, and alot of heat before something craps out. Their recommendation of 4000 20c lipo is way too low, but the rest of the info is good and should be listened to.

The 80% rule should also be applied to DOD (depth of discharge) as well. If you want your lipos to last as long as possible, only removing 80% of the total capacity (mah) from them is a good idea. Plane guys do this, but they usually time their flights in order to do this. You could probably do the same thing with a few test runs and a stop watch. Not sure if setting the lvc higher will gaurantee good result with trying to stay under 80% DOD.

Well yea, but you can't expect everyone with a MMM to buy a data logger. In any case, we all know to buy good quality batteries :yes:

My thoughts exactly!

Maxamps is trying to rate batteries in surge watts according to the rating of a motor?

Here we have a reputable President of a ESC/Motor company saying "Don't do it!"

:whistle: Hmmm.........whoever shall we listen to? :whistle:

I vote CASTLE!!! :yes:

i still think its a joke that the MMM will die if you use cheap cells, how come the MM never had that problem?

^^ oh cummon! it's exctly like trying to run a big block V8 sprint car on standard octane fuel!!
yeah sure, it runs..but really bady!!

The mm didn't have these problems cause it couldn't handle this kind of power period. How many people ran 5s on a mm? Not many cause it worked for some and smoked for others. The mst you could reliablly get on a mm was 4s and the heaviest you could really go was a light e-maxx geared conservativelly, or a 1/8 buggy geared for a track. I can almost gaurantee that 90% of the failures from poor batteries have been in heavy vehicles with high gearing that will stress even the best batteries.

Not too many people would run a 1515 sized motor with a MM either. The MMM just deals with more power.