What is this BS Castle is feeding this customer?

[jhautz]

Originally Posted by Joe Ford

You don't need a lot of current if you were to run a lower kv motor with light gearing...it's all how you use the controller. ;) For the R/C industry you're probably not going to find many people running NiMH cells with the Monster, but we had to put it up there or I'd be answering a lot of emails. ;)

But in the extra card that came with the MMM it said that it required a minimum of 75A continuous and over 125A burst. Why would this statement be accurate then?

[crazyjr]

Originally Posted by jhautz

But in the extra card that came with the MMM it said that it required a minimum of 75A continuous and over 125A burst. Why would this statement be accurate then?

I think its, for the new to brushless guys, that don't have the experience we have, to determine what loads we will put on them.

[Joe Ford]

Originally Posted by jhautz

But in the extra card that came with the MMM it said that it required a minimum of 75A continuous and over 125A burst. Why would this statement be accurate then?

That is with the 1515/1Y in a typical setup. I stated if using a lower kv motor and light gearing you could get away with NiMH. ;)

[Toyman]

I have a MMM on the way from Mike, I run Nimh will my 14 cell GP 3300's and 8XL work ok??? Steve

Originally Posted by Toyman

I have a MMM on the way from Mike, I run Nimh will my 14 cell GP 3300's and 8XL work ok??? Steve

and im close to that im running a 9xl and either 14 gp3300's or i built 2 8 cells packs, that i plan on running too. Yes i bought a lot of gp3000's along time ago.

[jhautz]

Originally Posted by Joe Ford

That is with the 1515/1Y in a typical setup. I stated if using a lower kv motor and light gearing you could get away with NiMH. ;)

Thanks Joe, I wasnt sure what your baseline was for "lower". Got it now. So all of this setup info is based on a 2200kv 1515/1Y on 6s? I would imagine running that same motor on 4s would not require the same battery capability either provided gearing didnt change.


Just to be clear can you confirm this for me...

Then with a 1512/3D (1700kv) shorter lower kv motor in a light 1/8 buggy and conservative gearing (35-40mph) I could run a lipo that isnt quite up to the 75A/125A specs and get away with it without damage to the Monster.

Sorry to be a pain, I just read all the bolony that has been posted the last couple days in this and "other" forums regarding the Monster and lipos that may not be up to the task causing the reported dead MMMs and I want to be clear is all. And hearing it directly from someone at CC is better than all the hearsay floating around at this point.

[xtremelimits285]

Originally Posted by jhautz

Thanks Joe, I wasnt sure what your baseline was for "lower". Got it now. So all of this setup info is based on a 2200kv 1515/1Y on 6s? I would imagine running that same motor on 4s would not require the same battery capability either provided gearing didnt change.


Just to be clear can you confirm this for me...

Then with a 1512/3D (1700kv) shorter lower kv motor in a light 1/8 buggy and conservative gearing (35-40mph) I could run a lipo that isnt quite up to the 75A/125A specs and get away with it without damage to the Monster.

Sorry to be a pain, I just read all the bolony that has been posted the last couple days in this and "other" forums regarding the Monster and lipos that may not be up to the task causing the reported dead MMMs and I want to be clear is all. And hearing it directly from someone at CC is better than all the hearsay floating around at this point.

+1

Joe,
i run a 8T with a neu 1515 1y on my mamba max an external bec, ive been running on my 3s2p 8000 maxxamps pack, gearing around 32-38mph max( ive been haveing no overheating an no problems an can max 20 min mains....
(can i gear up, up on 3s to 45 mph max..ON THE MMM)

can i keep running my 3s8000 pack(if geared under 45mph), or do i need to run my 4s6000, or 5s2p 8000 maxxamps pack???

BTW i always run low settings (never under 30% acclimit usuly 70%, an never run more then 5-low motor timming)my LVC is set at 9.2v for 3s on my mamba max should i change any setting for the MMM?

Whats best for 38-45mph racing (an last 20in mains)?
on the 1515 1y/f in a 1/8th scale truggy(trying to keep the weight down)
3s 8000?
4s 6000?
5s 6000?
(a 5s8000 pack is too heavy)
looking to buy another pack(have 3 allready)
thanks
gary a.

[nativepaul]

Originally Posted by jhautz

But in the extra card that came with the MMM it said that it required a minimum of 75A continuous and over 125A burst. Why would this statement be accurate then?

Good NiMhs are capable of that and more, holding reasonable voltage while doing it, just not for long, F5B flyboys were pulling over 300A from NiMhs in 3 second bursts before they switched to LiPos and boat and pylon guys were pulling close to 100A continuous, but at those levels your lucky to get half a dozen decent runs out of a pack before it either significantly drops capacity and voltage or goes pop.

[What's_nitro?]

Originally Posted by Joe Ford

Actually insufficient batteries CAN damage an ESC from ripple current. That's why we want you gents using batteries that are more than sufficient for your system. :)

Couldn't that be prevented by installing a diode on the battery leads (unless the MMM uses regen' braking)??? Seems like something that should be done if there is the slightest chance of it happening.

[Pdelcast]

Originally Posted by What's_nitro?

Couldn't that be prevented by installing a diode on the battery leads (unless the MMM uses regen' braking)??? Seems like something that should be done if there is the slightest chance of it happening.

The MMM uses regen braking -- has to, there is too much energy to try to dissipate as heat in the ESC, so the braking energy goes back to the battery.

Besides, the diode would just make the capacitors work HARDER, not less -- the issue comes when the power side impedance is so high that the capacitors have to work really hard to keep the ripple voltage low. When the capacitors have to work hard, they get hot -- if they get too hot they fail.

SO -- no resistors, no diodes, nothing at all in series between the battery and the ESC. The lower the battery to ESC resistance, the better for the ESC, and the cooler the ESC will run.

Thanx!

[What's_nitro?]

I see. Thanks for clearing that up. It wouldn't be worth using twice the FETs to handle braking just so people could use cheap batteries!

[Joe Ford]

Originally Posted by nativepaul

Good NiMhs are capable of that and more, holding reasonable voltage while doing it, just not for long, F5B flyboys were pulling over 300A from NiMhs in 3 second bursts before they switched to LiPos and boat and pylon guys were pulling close to 100A continuous, but at those levels your lucky to get half a dozen decent runs out of a pack before it either significantly drops capacity and voltage or goes pop.

100% correct...I'm one of those pylon guys...100A continuous plus in my F5D's...the batteries get about 10 cycles and then I throw them away. Same for the F5B guys. :)

For "getting away with batteries that handle less than 75A", NO, DO NOT DO THIS. If the controller fails due to ripple current we can't cover it under warranty, and you may lose your batteries in the process. Better to buy expensive, buy once.

[sleebus.jones]

friends don't let friends use cheap batteries ;)

[rcmonkey]

I will be using 6s1p A123 cells in my conversion that are rated at 69A continuous and 138A burst. So what you are saying is that unless I aim for silly speeds the lower continous current rating won't matter?

[lutach]

Originally Posted by Joe Ford

100% correct...I'm one of those pylon guys...100A continuous plus in my F5D's...the batteries get about 10 cycles and then I throw them away. Same for the F5B guys. :)

For "getting away with batteries that handle less than 75A", NO, DO NOT DO THIS. If the controller fails due to ripple current we can't cover it under warranty, and you may lose your batteries in the process. Better to buy expensive, buy once.

Is there any way to overcome this issue with the ripple current?