Are Zippy Lipos safe with a Castle MMM Speedy?

[Pdelcast]

Originally Posted by jzemaxx

Here is the problem with that logic. I have used these very same packs with other cheaper controllers (Turnigy 100HV) and as high as 12S and nothing has ever happend to those controllers with huge immense loads when I was doing speed runs. I also run the same exact packs on the HV110, and use to run them on the little old mamba max on 5S. NONE of those controllers have ever given me a problem and still use them on apps when the MMM dies. Now this controller has gone dead 3 times, I swap in my trusty HV110 or mamba max between service times and magically never have any problems. The only common variable being changed is the MMM. The batteries never change....

You just proved the point... The HV controllers are based on 60V processes -- the Mamba Monster is a 40V process.

If there was a problem that was causing voltage spikes during regenerative braking, the Monster could be damaged BEFORE the HV controllers.

That's why the Monster is rated to 6S and no higher. It can take bus surges to 40V.

[jzemaxx]

Originally Posted by Pdelcast

You just proved the point... The HV controllers are based on 60V processes -- the Mamba Monster is a 40V process.

If there was a problem that was causing voltage spikes during regenerative braking, the Monster could be damaged BEFORE the HV controllers.

That's why the Monster is rated to 6S and no higher. It can take bus surges to 40V.

What has me confused is all my race trucks are mechanical brake...reverse and brake are all but disabled.

[Pdelcast]

Now, that said, ANY battery that is pushed beyond its capabilities can damage an ESC.

Let me say that again:

ANY BATTERY THAT IS PUSHED BEYOND ITS CAPABILITIES CAN DAMAGE AN ESC.

AS CAN BAD CONNECTORS, BAD WIRING, AND BAD SOLDER JOINTS.


We have gotten so oblivious to the fact that we are harnessing thousands of watts in these setups -- any problems in the system can cause problems with other components in the system very quickly.

So we must be VERY careful NOT to push batteries harder than they can handle.
The very same is true of Motors -- and people seem to accept the fact that certain motors can only be pushed to a certain point before they fail.

Why do the same people not understand that a battery pushed beyond its capabilities can damage the ESC?

The ESC relies on the battery to both SOURCE high currents without significant voltage drops, and to SINK high currents without significant voltage rise. If the battery cannot hold the bus voltages within a reasonable voltage, then the setup is PUSHING THE BATTERY TOO HARD.
A battery needs to have the ability to sink braking energy during hard braking, and take that energy back as charge energy. If the battery can't take the energy back quick enough, the voltage on the bus will rise, and eventually it could get high enough to damage the ESC. We do bus voltage monitoring on the Mamba Monster, but if the battery is REALLY bad, the voltage can rise faster than the MMM can respond to it.

It all comes down to this: Don't push any parts in your system beyond what they can REALISTICALLY take. This includes motors, batteries and the ESC.

Just as some motors are better than others, some batteries are better than others. You can't expect a $25.00 Chinese motor and a $250.00 Neu motor to perform on the same level. Same goes for Lipos. There are applications where cheap lipos and cheap motors WORK JUST FINE -- but there are other applications where they may perform below par.

Patrick

Originally Posted by RC-Monster Mike

This proves the point more than it disproves it. None of those batteries are "high end" batteries and would all be prone to exactly what was discussed in the linked thread. Jim (Tekin Prez) made a couple sensible, descriptive posts in that thread regarding the "potential" pitfalls of lower end batteries. It is a fact. I am not here to call out any specific manufacturer or seller, but many packs do tend to be over rated, inexpensive packs that are popular due to their inflated specs, inflated marketing or low price(or combination of the above). Everything has its place. If your particular setup or driving style, etc. allows you to have great success with your particular "low end or mid range pack that happens to be overrated ", but you aren't anywhere near the particular pack's limits, then you got a good value. If you are pushing things, you will not only notice the performance difference with a good pack, but will be less likely to experience failures.

I am not saying the battery was the cause or wasn't the cause of the failure in the discussion - I don't know the guy, don't know the car and wasn't there. I do agree with the logic regarding the pitfalls of lesser quality cells - particularly in 1/8 brushless applications that tend be very hard on equipment. Maybe the pack was the cause. Maybe it was just one of several factors that caused the failure. Maybe it had nothing to do with the failure at all. It certainly COULD have been a major factor in the failure and the advice to use a quality pack is sound advice.

This debate will continue as there arent the standards we need to compare batteries. One companies 35C is someone elses 25C. Frankly i really like the zippys and they are holding up so well i bought more. When i compare them in my emaxx and erevo with MMM and 2200CastleNeu 19/52 gearing against the Neuenergy packs the Neus get much warmer in the
same application. The truck "appears" to be performing very similarly with the different packs. no I'm not using a tester but i am comparing straight line visual speed and speed on the track. No i havent had them for a year and a 100 cycles so who knows how long they will last. I can tell you my 6000 and 8000ma max amps have puffed in same application but my 35C8400 maxamps packs have not and seem to be a huge improvement over the previous maxamps technology.
It would be nice if someone like MIKE would take samples of the top batts out there and do some real testing for us then we can pay for the performance we really need.

secondly i have had a bad 2075 traxxas steering servo take out a MMM ESC
so their are many variables. If you want to go 60 you are going to break "something" on almost every run.

This thread is interesting for sure. With that said, I run Zippy lipos in my Savage Flux. I run the soft case 3S 3500 30C constant/40C burst and the soft case 3S 5000 30C constant/40C burst packs. 0 problems and I've run them in this truck since early February. The truck uses the stock 20/44 gearing, runs 6.5-7" tall tires and is tuned with Castlelink, specifically the throttle punch and throttle curve. The auto lipo cutoff is set to 3.5v per cell. Firmware is 1.21. The performance of the truck, even when neutered with Castlelink, is superb. The batteries never get hot and the ESC never gets hot-the fan kicks on and does its job like it should. From my experience, I'd be hard pressed to not tell somebody to use Zippy packs.

I will add that Castle really has nothing to gripe about because HPI and Traxxas both state in their user manuals that you can run anything from a 6 cell nimh stick pack up to a 25C 3S lipo with the Mamba Monster. Certain Zippys meet that requirement, and the ones I run do meet it. If Castle has a problem with us running Zippys, they need to sit down with HPI and Traxxas and get things sorted out with the battery pack particulars. And they need to let the end user know, in writing, what should be used and what shouldn't. From my perspective, it appears Castle is not on the same page as HPI and Traxxas, or vice versa. And this is a major issue considering the amount of Savage Fluxes and BL E Revos that have been, and will be sold. Not to mention all the "loose" Mamba Monsters that have been sold and installed in other kits or conversions.

[fastbaja5b]

Agreed I have fired off an email to Joe Ford about 8 or 9 hours ago, and am waiting on a response, I only asked as I want to get a pair of 3s for my Flux but finding that post and their "alleged" replies from Castle support, I thought it best to check before I throw some coin at it.

the 4s set up I run is 2 * 5000mah hard cased packs at 30C so I am fairly confident in that set up.

[RC-Monster Mike]

I was not speaking to any "specific" instance so much as suggesting that the lower quality batteries CAN cause problems. Perhaps the MMM is more prone to this issue than other escs due to lower internal resistance or something else specific to its construction or specifications. That wasn't my point. My point was to state my agreement that better batteries are indeed better. Better performance. Better cycle life. Less likely to cause esc problems(Better). Regardless of how prone any particular esc is to this issue, it will be less prone when quality batteries are used. That is my logic.
So - IF the MMM or any other esc is prone to failure due to lower quality cells, then my "flawed" logic suggests that better batteries lessens the possibility of this happening. The fact that the manufacturer recommends high quality batteries to begin with is no secret, either.
Is this illogical?

[RC-Monster Mike]

To add to the logic - most people report increased power in the otherwise identical setup when switching to the MMM controller(myself included). Perhaps the trade-off is that this more pronounced and available flow of power goes both ways, making the controller more prone to failure due to "issues" more commonly found in lower quality batteries. I am not the manufacturer and I did not join the discussion to offer anything other than my thoughts on batteries causing esc failure - using better batteries will yield better results in all cases.

[BrianG]

To add to what Mike has said; The controllers mentioned are either airplane ESCs (HV110, turnigy) or ESCs with a lower current rating (MM). This could be due to FET choice, and/or ESC construction. It has been stated that an airplane ESC is not designed for the burst currents we see in car applications, so they have a higher total resistance (in FET choice, PCB traces, etc) so they tend to not to funnel as much energy as an ESC designed specifically for car use. And lower-current ESCs, like the MM, also have a higher total resistance, which helps to limit the potential current spikes.

An "ideal" ESC would be one that is as transparent as possible to current flow. This means 0 ohms of resistance. While that ideal is not practical, car ESCs designed for 1/8 scale (or larger) vehicles will have less resistance because of the currents they are designed to pass.

Also, lower-end packs tend to have higher internal resistance, which tends to increase the ripple current from a powerful system. I am willing to be that adding a few more low-ESR caps to the MMM when used with lower-end packs will drastically reduce ripple currents. Yeah, it's a band-aid, but not for the ESC, it's to compensate for the lower-end packs.

[BrianG]

Patrick, since you're on here, I have a few q's about the MMM:

- What is the voltage rating of the clamping device used in the MMM?

- If the EMF braking spikes are excessive/numeruous enough, is there a chance of that device blowing while not being obvious to the user (which would then allow those brake spikes to now reach the battery)?

- And, which version of MMM was this device added? I say this because my V1 had what looked like such a device added after manufacture.

[skellyo]

Originally Posted by BrianG

Patrick, since you're on here, I have a few q's about the MMM:

- What is the voltage rating of the clamping device used in the MMM?

- If the EMF braking spikes are excessive/numeruous enough, is there a chance of that device blowing while not being obvious to the user (which would then allow those brake spikes to now reach the battery)?

- And, which version of MMM was this device added? I say this because my V1 had what looked like such a device added after manufacture.

I'm not sure if the V3 uses the same device or not, but the device in your V1 that was added is detailed here:
http://www.rc-monster.com/forum/show...9&postcount=22

[RC-Monster Mike]

"all but disabled" or actually disabled? The motor itself has mass and can result in significant back emf when applying brakes to slow itself down(Brian and I discussed this yesterday in fact regarding some tests he performed). IIRC, the motor in question produced nearly 30 volts of back emf when the brakes were applied - using a 4s pack to accelerate. No load other than the motor itself.

[BrianG]

lol, Patrick. So, wait a minute, I'm gonna go out on a limb here and assume you are trying to say that any battery that is pushed beyond its capabilities can damage an ESC?

And, I for one am amazed at the power levels these little devices control.

[Pdelcast]

Originally Posted by BrianG

lol, Patrick. So, wait a minute, I'm gonna go out on a limb here and assume you are trying to say that any battery that is pushed beyond its capabilities can damage an ESC?

And, I for one am amazed at the power levels these little devices control.

Brian, yes - -that's exactly what I'm trying to say.

Really, if any component in the drive line is pushed beyond it's power handling capability, it can potentially cause damage throughout the entire drive line. For example, if the rear end is pushed too hard and it seizes, that could cause damage to the spur gear, the pinion, the motor, the ESC and the battery (potentially...)

We just need to be careful about how we match components, and make sure that we make careful choices.

For example, I would never run a 6S 1515 MMMM system on a 6S 1200mah Lipo -- I know the Lipo would fail under those conditions (100C+ currents) and might also damage some of the other components in the system (ESC in particular.)

[Jabe]

Ill like to protect my controllers, so i was thinking about adding this little component and capacitor parrel to my battery connectors, to protect esc from voltage peaks and drops.
Im using batterys that should power my system in theory, 240A (in theory) continous should be enough.
What castle has to say about that? Would it be good idea?