Are Zippy Lipos safe with a Castle MMM Speedy?

[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 :-).

[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.

[phatmonk]

What corners are being cut with these Zippy batteries that they can sell them so cheap?And cause these issues?

[Arct1k]

I'm for the software Patrick - I'd rather have something trip or lower (but i'm sure acceptable) performance than a smoking esc.

I toasted a couple of MM early on and paid for them to be replaced as used in 1/8th scale - Even though well rated batteries in reality I believe a component was ripple - since the failures I then added extra caps and never had a failure since.

[johnrobholmes]

I would rather see the ESC limit instead of have it slowly get killed from ripples.

[e-mike]

me too...+1 for the software....i take very care of all my mmm.....this kind of devise could it be a great solution for a bad set-up.....

[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.

[shaunjohnson]

[QUOTE=Dagger Thrasher;264723]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)?
QUOTE]

yes i highly like this idea!!!
because of the people who do KNOW about these ripple issues can turn it off to get good performance...but doing so knowing the limits of the battery.
so if i were to run 6s 5000mah zippies then i could turn off the power limiting so i dont lose performance, but i'd be gearing it down anyway as not to get any ripple current.

very good idea...yeah it's not fair at all that castle has had to replace all of these ESC's
shaun

[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

[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. :)

[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.