Darn...no over-volting the Monster
 

Hey people,

Just thought I should post some info from Patrick over on RCZ that I read. It looks like running over 6S LiPo on the Monster ain't gonna happen. Here's why:

[There is] a 28.0V TVS (transient voltage suppressor) on the Monster Maxx -- so you will smoke the TVS with a 7S pack, and then smoke the whole controller the first time you do any serious braking with 7S.

6S is a hard limit. Nothing higher than 26.0V.

Patrick

Link: http://forums.radiocontrolzone.com/s...d.php?t=247907

He also said over on RC Groups that the switching BEC has a constant current rating of about 4A (runs warm) and peak of 5A. Should be plenty for our servos.:smile:

It looks like he *might* be planning on an 8S version, and maybe a 12S controller down the line...but that's just purely my speculation. I just wanted people to know about the 6S limit, in case they hadn't read that and try to run their new MMM on 7 or 8S. Ain't gonna happen. :(

Very good information. Looks like 7S A123 is doable tho. However my hyperion won't balance 7S. I still don't know why they make a 12S capable charger, and then only a 6S capable balancer. </rant>

I dont plan on going over 6s but still good information to know.

No fear boys :) I'm sure there will be tweaks and mods to get the MMM going over voltage. If it's only one component, I'm sure it will get modded properly.

I think most folks will find it sufficient on 6S (like me), but then again...

It will balance up to 12S. You just have to get 1 more LBA10 balancer & harness. You slave the second balancer to the first & you can balance up to 12S. The LBA10 manual has instructions showing you haw to do it.:party:

Hmmm...such a disapointment. I've been waiting for this to come out and now it's extremely dangerous to run it over 6s.

I can under stand that, but then again- if it says 6s on the label, then 6s is all you can run; why call it 6s if its really 7~8s?... I think 6s2p of A123 will suit me just fine.

Well, they call the MM 3s, and it's usually 4s-5s no problem. I say we'll see what we see. 6s is plenty for me, but I'm sure people will be finding ways to push them farther.

The reason why CC said the Mamba Max could only do 3s is because 4s would push even the 4600kv CM36 motor over the 65,000 rpm limit. The ESC was clearly made for up to 4s, Castle Link has a cut-off for 4s... but you're gonna need a UBEC.

killing a component is not the same as extremely dangerous. I think its disrespect to castle to call it such a disappointment. I'm stoked that there is finally a 6s capable purpose designed car controller - im sick of these ludicrously overpriced boat controllers, or the esc that totes it can run at 6s but blows up when your try.

A solid 6s controller, and it is so cheap. Under $200 is unheard of for these specs yet. With any proper 6s or lower setup I really don't think I could overwork the ESC unless I got a 5B or a 25lb emaxx with super swampers.

I am aware of slaving the two LBAs, but I think you might have missed what I said. It will balance two separate 6S packs for a total of 12S. It won't balance a single 7S pack. That's what I'd want to do.

I don't think there is a 7s hyperion balance adapter - I think you get a 3s and 4s adapter on the pack....

You link the 2 lba10's with a link cable and it will balance it as one battery...

You can, other brands of packs also just have two balance leads hanging out.

what voltage is a 6s right off the charger? how about a 7s off the charger. maybe you could wait a while or not charge it to 100% capacity and the voltage would be low enough. Or am i just smoking crack?
personaly all i need it to do is 16nimh. then maybe some of those li-ion sony cells. in a 5-6s2p config

A 6s is 25.2 volts fully charged so that only allows .8 of a volt before melt down.

I think its disrespect to castle to call it such a disappointment.

You're right.

Castle dudes, I'm sorry I disrespected you...:sarcastic:

LOL...all good man. Just don't do it again. :whip:

7s A123 is max, 6s lipo max. You guys can do a LOT with 6s. :yes:

I personally think the TVS is a great idea! It keeps high voltage spikes from getting to the battery during heavy braking, which can't be good for lipos.

Didn't GriffinRU do that on hid modded MM?

Dunno, I don't remember him doing that. :neutral: I do know the topic has been raised before...

Just found it. He did do it.

So Joe, I'm gonna ask the same damn question again:

Are you planning on releasing a HV version of the Mamba Monster?

Patrick said an 8S version would need just a few changes done to the components, but a 12S version will be gladly excepted. I'm done asking. So you guys feel free to ask for one.

Just get us a 8s version out and this world will be a better place for us, Castle.

Anything between 8s and 12s would be good. Seems like using higher voltage on the cheaper feigao motors works better and produces less heat.

But the MMM will be very welcome, I am looking forward to it!

8S / 12S version of the MMM
 

Believe me, I am looking at doing an 8S or 12S version (or both) of the MMM --

My question is:

Would people be willing to spend an extre $120.00 on a 12S MMM? That's really the minimum extra it would cost to do a 12S controller...

Also, a 12S system would more than likely be Opto, to keep the motor noise from the radio. So would require an external power source for the RX/Servos.

An 8S system would certainly be easier, but still a little more costly than the 6S system.

Patrick

I guess the extra $120 will be because of the controller being completely different from the 6S right? I can work with Opto as most of my HV controlelrs are Opto. I'm in for 4 maybe more 12S units as I can use 8S and 6S as well with it.

Off topic: Can a simple forward/brake software be made for the SHV if the hardware is not compatible with the Mamba software?

The difference in cost is because of the difference in number and price of the MOSFETs. Double FETs with higher price for a 12S system. Remember, MOSFET resistance goes up by the square of the voltage.

There probably won't be any forward/reverse SHV software made available. It just doesn't have the hardware for braking/starting heavy loads.

Patrick

BTW, I'm in China now, checking progress on the Neu/Castle motor assembly line design. Pretty close to building motors. If I get a chance, I'll post some pics.

Patrick

So we are talking around 300 bucks for a 12s capable controller that will offer forward, brake and reverse, and be computer programable? I would buy it, as the only other options I can think of are the mgm escs, and they appear to have issues. I have a feeling that you would sell a few, I know that I would do a large scale conversion (1/5) if a decent hv car esc was around. I think that an 8s capable controller would be popular as well. The benefits of hv are quite aparent to me, less heat and more punch at almost any speed. I know cc like to cater to the extreme rc crowd, and this would be a nice flagship car esc. Plus cc service is second to none, which always helps!

Opto is not too bad, escpecially if you can make a hv version of the ccbec! Do have any any plans to bring out a hv bec? Say capable of 12s input?

That sounds good. Count me in for 4 or more 12S Monster Max. All I'm asking for the SHV is forward/brake. I'm not going to be putting a high load on it, but what is the highest available AMP rating the small versions (Not the big 250A one :lol:) have?

I called you on Friday, then I remembered you told us you will be there until the 8th. I sent you an e-mail, but I'm not sure you received. Would you be able to do motors for customers specs and designs?

I would be in for a 12s ESC. I have always wanted to try HV as the highest I have gone is only 4s. But with the MMM, I will probably try it to 6s, and if the HV ESC came from CC, I'd try a 1/5 scale truck conversion too.

the thing is 6s and a good efficient motor is gonna push(Plenty fast) any 1/8 buggy, truggy, monster truck no matter how much aluminum you have on it, and thats what the mmm is ment for. not to power custom 1/5 scale 25lb monster trucks. I run 14 old beat up, vented gp33000's. that on a 9xl is almost too much power for all but strait speed runs. keeping it on all 4's off the line is a chore, unless i loosen the sliper a whole lot. So someone tell me why 6s with a neu isnt gonna be enough? :P

Well, for a start, higher voltage generally runs cooler, and allows for cheaper lipos, as the c rate and overall size can be smaller. Until you have run a hv setup it is difficult to understand the difference. Also, depending on the lipo, the lower amp draw due to increased voltage provides more performance at higher motor loads, as the batteries are not working as hard as a 4s setup would be. 6s is good, much better than 4s in my experience. Plus the cheaper feigao motors seem to run cooler at higher voltages, as their is less current going thru them. The higher voltage helps the ineffecientcy of the motor a bit.

:yipi:

Simple:

Lets say you're looking for 2HP or 1500 watts. With 6S you will need at least 68A to get that. Now if you had 12S all you would need is 34A. With 6S a good motor for a buggy would be the 1512/2.5D and for 12S would be a 1512/2.5Y. Now if you want a good motor for a truggy with 6S would be a 1515/2D and for 12S a 1515/2Y. Now those would be a nice choice for racing. Guess which motors will be more powerful, run cooler and more efficient.

That doesn't explain why 6s wont be enough. All your saying is that 12s is better than 6s, while you don't prove how much of an advantage there actually is (where is your actual data?) Not everyone is trying to break the land speed record with a monster truck. I would be more concerned about lipo failures than having a setup that runs 20 degrees cooler than what is already acceptable. The more cells there are in a pack, the more vunerable the cells are to undervoltage, since a weak cell has to go way below the safe limit before the mean voltage of the cells in the pack triggers the cutoff.

With higher voltage you can run a lower KV motor and this setup will pull less amps meaning less heat than a lower voltage and higher KV motor, and since your motor is pulling less amps with the higher voltage setup you can run a lower capacity pack to get the same runtimes. Your motor will pull a certain amount of watts all the time, Volts X Amps = Watts, the average 1515 or XL size BL motor will pull 1500 watts, if you want to compare different setups you can divide the 1500 by the voltage amounts and this will get you in the ball park there are other variables Gearing, weight of vehicle, wheel size.