Are Zippy Lipos safe with a Castle MMM Speedy?

[MrMin]

Patrick...I dont think it is fair for you to replace controller after controller if this really is the problem... Brian did a good "no load regen brake test" somewhere recently and made some pretty interesting observations wrt tvs, current voltage... Would like to know what the situation looks like under load :-) .. What numbers are we talking about in worst case?

I think it is a good idea to keeps in the safe zone with the ripple and batt checking....I personally run zippies and dont mind a little less power and more reliability...-> I can also however imagine there are some who want to squeeze every last drop of power out of it and run everything at the limits, hot & cold and exploding if needs be(though I imagine they will have better batts :-) )

Maybe those riskers can maybe disable this function (with the effect of guarantee loss).

Help..I'm gonna get flamed...

[Dagger Thrasher]

Patrick, that sounds like a great idea to me. It'd certainly help sift out the all the lower-quality packs out there too, as active performance-limiting would make it all the more obvious if a pack is struggling...as well as obviously preventing ripple deaths.

Perhaps it could be included as a check box in Castle Link? Allow people to turn off "Dynamic Power Limiting" (or whatever you'd call it) if they really want, but add a disclaimer that warns the user of possible damage to the ESC or battery if they're using cheap packs (and that Castle strongly recommend that the feature stays enabled)?

Maybe you could also add an LED flash code that warns the user if their packs are struggling too much while the feature's turned on? That way, it'd take the guess-work out of whether performance is being limited or not.

[BrianG]

Originally Posted by Pdelcast

And for those who are interested...

We've been struggling with whether or not to release a version of software that actually measures voltage ripple, and limits performance based on how the batteries perform.

On one hand, it would prevent a lot of damaged ESCs, and batteries -- when users are pushing batteries insufficient for the application.

BUT, on the other hand, a lot of people who are running "marginal" systems will see a performance decrease, and might yell "FOUL!" at us for releasing software that would actually lower the performance of their system.

As it is, very few controllers actually get damaged by ripple voltage/current -- but the people who damage controllers this way don't just do it once and then learn a lesson. They tend to destroy controller after controller with the same bad setups. And then they blame US for making a defective product.

Brian, and others, I'd be interested in hearing your thoughts on this...

Yes, I'd definitely like this. And I'm sure it would help reduce warranty claims (and lost revenues on your end). Just be prepared to increase manpower on your tech support lines because I have a feeling there will be an influx of calls!

Seriously though, this IS a great idea!

One more suggestion; when the ESC limits performance because of ripple, have the LEDs blink some kind of error code so the user knows what to watch out for. And while you're at it, add similar error codes for temperature extremes, and any other condition you can measure. These codes should "latch" so that the code remains (even if the condition goes away) until the ESC is unplugged. It would be like a car's CEL.

And while you're in a receptive mood for suggestions, here is another thread to ponder over: http://www.rc-monster.com/forum/showthread.php?t=18832 After all, gotta give your firmware developer something to do!

[sikeston34m]

Originally Posted by Pdelcast

And for those who are interested...

We've been struggling with whether or not to release a version of software that actually measures voltage ripple, and limits performance based on how the batteries perform.

On one hand, it would prevent a lot of damaged ESCs, and batteries -- when users are pushing batteries insufficient for the application.

BUT, on the other hand, a lot of people who are running "marginal" systems will see a performance decrease, and might yell "FOUL!" at us for releasing software that would actually lower the performance of their system.

As it is, very few controllers actually get damaged by ripple voltage/current -- but the people who damage controllers this way don't just do it once and then learn a lesson. They tend to destroy controller after controller with the same bad setups. And then they blame US for making a defective product.

Brian, and others, I'd be interested in hearing your thoughts on this...

Hi Patrick,

IMHO, Batteries with poor quality ALREADY limit performance. Releasing a new version of software that measures this and protects the ESC is a great idea if you ask me.

If I understand what I'm reading correctly, this could actually lead us to match our systems better based on what the ESC can do safely.

How would it limit performance though? Acceleration isn't where the damaging ripple current occurs, is it? It's during braking.

I can only imagine what happens when all of that inertia from HARD acceleration, and a motor that's suddenly turned into a generator, comes crashing back through the ESC. With a poor quality battery, it just isn't going to accept the current. Things get critical.

If only Batteries could charge as quickly as they discharge.

Thanks Patrick, for giving me a better understanding of what's going on. I really do appreciate it. You have a way with words. A good teacher.

Even someone who does understand, and doesn't present it in an understandable way, only leads people to confusion or false assumptions.

i like that feature in a set up. It would be AWESOME if the user could choose to run it on or off

[fastbaja5b]

I'd be all for it, if my esc tripped out based on this protocol I'd know those packs aren't suitable.

Still I don't know if I should or shouldn't get these Zippy packs, they are 5000mah 3s rated 20c-30c (whatever that is) but maybe it's all too risky and I should stay on 2s

[MrMin]

Originally Posted by Pdelcast

The better the battery, the less ripple current ... so what we do is size the capacitors to something that is reasonable, and use a high switching frequency to optimize the capacitance (higher switching = lower ripple current.)

But, the enemy is ripple voltage -- and the better the battery, the less ripple voltage.

The switching is on the motors, not on the dc source. If the TVS spikes a big cap it should smooth it out - i suppose a batt is a big cap, so patrick and brian are correct. But I imagine when the motor throws too much back that the load has to be disipated somewhere....The bat is usually a good place. But cheaps batts will not handle it. Can't the excess be clamped off to a big resistor or light bulb or maybe some fireworks and pretty sparks ??

I notice also that patrick and brian never like band-aid solutions like fans and heat.. Rather be efficient and never generate the problem in the first place...typical two too good engineers :-).

[RC-Monster Mike]

I think software is a great idea. Actually, I think it is how it SHOULD be. And I would suggest that the people who lose performance and "cry foul" should be crying foul to themselves. If you buy a high end sports car, you want to run good gasoline. If you run it on pump gas, it won't perform well, may "ping" and foul plugs and generally will be less than desirable. Brushless is the same - good batteries = good fuel. Bad batteries = pump gas, "ping", fouled plugs and less desirable. :)

[MrMin]

Originally Posted by MrMin

The switching is on the motors, not on the dc source. If the TVS spikes a big cap it should smooth it out - i suppose a batt is a big cap, so patrick and brian are correct. But I imagine when the motor throws too much back that the load has to be disipated somewhere....The bat is usually a good place. But cheaps batts will not handle it. Can't the excess be clamped off to a big resistor or light bulb or maybe some fireworks and pretty sparks ??

I notice also that patrick and brian never like band-aid solutions like fans and heat.. Rather be efficient and never generate the problem in the first place...typical two too good engineers :-).

Patrick -- quick question -- are you using a transorb to clamp the overvoltage??

[Pdelcast]

Originally Posted by MrMin

Patrick -- quick question -- are you using a transorb to clamp the overvoltage??

Yes -- but remember, there is a limit to how much power a transorb can absorb. They claim some really high amp clamps (which is true) but they can only absorb those high amperage for very very short periods of time.

[Pdelcast]

I like the idea of making it a configurable option. Richard and Jon (my main software guys) are out of town until Friday, but I'll forward them the postings here. I'm sure they could add the voltage ripple detection limiting as a option (checkbox option) in Castle Link.

[fastbaja5b]

...ok so is that a yes or no to Mr Zippy?

and while I am here, can I run this flux with the 20t pinion, this thread here:
http://www.ausrc.com/forum/showthread.php?t=15868

They are blaming a smoked esc on not running a 25t pinion on 6s, wheras on this forum I was under the understanding that more volts = gear down to get less amps and therefore less heat.

So what is it?

Are Polyquest 5000mah 25c 3s packs sufficient?

I've had my Flux for 2 wks this Fri and have been running it as 4S on pr of 2S 5000mah 25C NeuEnergy lipos - after 20+min run, esc, batts and motor are only warm, so I think that setup's been fine.

I've been looking at a 6S setup - a pr of 3S 5000mah, 25/50C PolyRC XP lipos. I have same question - these good enough?

.

[hemiblas]

I think the software limitation is a good idea. I would hazard to guess that 99% of the people that run these things dont have a clue about what we are talking about. They just want a reliable esc that will work with whatever they throw at it. Most people also cant afford the high end batteries to get the most out of these setups anyway and they could fall into a trap by using the cheaper batteries and gearing up. I have zippies, truerc batteries and dont have any problems with my 2 MMM. Its like patrick said, its running the system within its means. I dont go out and gear for extreme speeds with my batteries so I dont have any trouble. The typical person however has no clue that any of this could happen. The fact that C ratings also arent standardized just makes it even more difficult even for those of us that know what are doing.

[hootie7159]

+1^.....people that use zippy's or truerc's and gear-up for 65mph with a small motor in an 1/8 scale rc and do continuous speed runs up and down the block until the lvc cuts in or people that bash with ridiculous speeds on smaller lipos are the ones who ruin their setups....i feel that 50mph is plenty for bashing and 40-44mph on the track is more than enough...just because it says "65mph out of the box" doesn't mean you should constantly be pushing for that ridiculous mph pack after pack (you'll most likely break something on the car anyways:)).....i've been running both my MMM's on 4s 20-30c zippy's in both an sc8 and rc8t (geared 40mph&44mph respectively and both without fans) for a couple months now i've had great temps and run times.....the software would be a fantastic idea!!!