Are Zippy Lipos safe with a Castle MMM Speedy?

[lincpimp]

Back to the OP, the zippy packs you mention will do fine IF YOU GEAR IT BACK DOWN SO IT DOES AROUND 45MPH ON 6S

PLEASE RE-READ WHAT I JUST TYPED, SAY IT ALOUD A FEW TIMES TILL IT SINKS IN. WITH STOCK GEARING THOSE ZIPPYS WILL GET HOT AND PUFF!

A 5000 20c lipo should be able to output around 100amps. That would not be enough for an 1/8 MT geared for 45mph on 4s, you need 150amps or more for 4s useage with that gearing. Now on 6s those cells should be fine.

Look at it this way, a 4s 5000 20c lipo can do 1480watts (theoretical max, no losses factored for this number) at 75% it can do 1110 watts, or 1.5hp, not enough for a 12lb truck with tall gearing.

A 6s 5000 20c lipo can do 2200watts, factor in about 75% effecientcy, and you have 1650 watts, or 2.2 hp. I would not run a MT on 6s with any cell spec'd lower than the 5000 20c you mention. Unless you plan to run 35mph, then you can run less capable cells (maybe even maxamps).

A 12lb truck doing 45mph uses some juice. A good rule of thumb, is 150amps for 4s 125 for 5s, and 100 for 6s. If you plan to squeeze out the 60+ mph claim on the flux, 2 polyquest 6000 25c 3s packs in series will be the best bet... 2500watts after losses, or 3.3hp...

[hemiblas]

Someone at the traxxas forums is setting a Revo land speed record with the MMM 2200 combo and some hobbycity lipos.
Quote:
The good news is that everything held together! The bad news is (and only if you call it bad news) I didn't hit 80. It did 76.7 I think that is all the stock truck will do with the cheap 3s Zippy Rhino 4900mah 20c batteries. I used 26t pinion and a 53t spur. I have on order a 25t mod1 pinion and a 34t mod 1 spur. Plug those numbers into the calc for the fun of it. Here is a pic of the ride height.
end Quote

The zippy's cant be that bad if they just set the speed record for an E-Revo. lol
At the end of the day that thread is good publicity and will get people excited about this stuff. The last thing they want to see is a post about how he is going to blow his MMM due to ripple currents. Sometimes doing great things on a budget is more satisfying than dumping hundreds of dollars on some quality batteries that we know will break the record. After that last post everyone is going to be putting MMM's in their trucks trying to beat that last guys record. I'm not sure if thats a good thing or not though.

[lincpimp]

Originally Posted by hemiblas

Someone at the traxxas forums is setting a Revo land speed record with the MMM 2200 combo and some hobbycity lipos.
Quote:
The good news is that everything held together! The bad news is (and only if you call it bad news) I didn't hit 80. It did 76.7 I think that is all the stock truck will do with the cheap 3s Zippy Rhino 4900mah 20c batteries. I used 26t pinion and a 53t spur. I have on order a 25t mod1 pinion and a 34t mod 1 spur. Plug those numbers into the calc for the fun of it. Here is a pic of the ride height.
end Quote

The zippy's cant be that bad if they just set the speed record for an E-Revo. lol
At the end of the day that thread is good publicity and will get people excited about this stuff. The last thing they want to see is a post about how he is going to blow his MMM due to ripple currents. Sometimes doing great things on a budget is more satisfying than dumping hundreds of dollars on some quality batteries that we know will break the record.

Ok, so this genius is going to go from sucessfully running gearing that specs out at 78mph with no tire ballooning, to gearing that specs out at 117mph... Wow, this guy is a sharp one... Going up a few teeth at a time is the way to do it. I doubt his new gearing will do as well as the old setup, as it will most likely stress the batts to the point they will puff, or worse.

I would like to see him run those packs till they hit the lvc and see what kind of mah he can put back in them, if they even hold up. I have a feeling that he may get half of their rated capacity back in, if that. A few runs is all they will give him, which is fine as speed trials are not ususally done repeatedly without a charge and cool down period.

So what has he proved? Newer lipo formulation resists puffing better than the old stuff. Sure he got his revo to go fast, and if that is his thing so be it. That setup will not have good temps and the lipo will not give many cycles at that load. So he is effectively ruining a good lipo, and putting the rest of the system at risk in the process. All so that a bunch of whining kids can "congratulate" him on having the fastest erevo. Kinda like being the worlds tallest midget IMO.

Now if he had used better packs he would have hit over 80mph, and not overtaxed his packs. So his battery investment would actually be an investment.

Bottom line is that we do not see Nic Case overgearing his setups and using cheaper batts to achieve his goals... Going fast costs money, and wears components out quickly. Not trying to rain on anyones parade here, just want to shhow things for what they are. Every noob that sees what he is doing will think that he has a solid setup, and waste their money on it too.

[shizzon]

dont know about you guys but i find my E-revo geared for 45 is plenty fast for bashing....then again im not one to just drive in straight line. to each there own but i am simply uninterested in trying to get my E-revo up to 80 mph as the only i could do with it is drive in a straight line a couple times before bringing it in to cool down....Ill take my 25-30 min of playtime as a reasonable speed any day.

[hootie7159]

Originally Posted by shizzon

dont know about you guys but i find my E-revo geared for 45 is plenty fast for bashing....then again im not one to just drive in straight line. to each there own but i am simply uninterested in trying to get my E-revo up to 80 mph as the only i could do with it is drive in a straight line a couple times before bringing it in to cool down....Ill take my 25-30 min of playtime as a reasonable speed any day.

+1^

[hemiblas]

Originally Posted by lincpimp

Ok, so this genius is going to go from sucessfully running gearing that specs out at 78mph with no tire ballooning, to gearing that specs out at 117mph... Wow, this guy is a sharp one... Going up a few teeth at a time is the way to do it. I doubt his new gearing will do as well as the old setup, as it will most likely stress the batts to the point they will puff, or worse.

I would like to see him run those packs till they hit the lvc and see what kind of mah he can put back in them, if they even hold up. I have a feeling that he may get half of their rated capacity back in, if that. A few runs is all they will give him, which is fine as speed trials are not ususally done repeatedly without a charge and cool down period.

So what has he proved? Newer lipo formulation resists puffing better than the old stuff. Sure he got his revo to go fast, and if that is his thing so be it. That setup will not have good temps and the lipo will not give many cycles at that load. So he is effectively ruining a good lipo, and putting the rest of the system at risk in the process. All so that a bunch of whining kids can "congratulate" him on having the fastest erevo. Kinda like being the worlds tallest midget IMO.

Now if he had used better packs he would have hit over 80mph, and not overtaxed his packs. So his battery investment would actually be an investment.

Bottom line is that we do not see Nic Case overgearing his setups and using cheaper batts to achieve his goals... Going fast costs money, and wears components out quickly. Not trying to rain on anyones parade here, just want to shhow things for what they are. Every noob that sees what he is doing will think that he has a solid setup, and waste their money on it too.

You make a lot of good points in your post. Speed costs money and if you cant pay then dont play. Just trying to provide some insight on why Castle needs to protect the speed controllers by whatever means they see fit.

I still think its funny that a pair of 4900mah Rhinos hold the record over there.

[emaxxnitro]

Yeah if he used better packs he will go faster. But still I can't get my erevo over 60 without it wheelieing and I use better packs 30c 5000's and a neumotor. If he where to use some poly quest or neuenergy packs he could see 80 possibly 85 mph but it's impossible to explain all of this stuff to the trx msg b members with out them crying or giving birth

[pasan]

I use only Zippys in both my E-Maxx and E-Revo. I've bumped up the gearing quite a bit on the E-Revo sometimes to 22/58 and do a one or two speed runs a week, perhaps for about 5 minutes each session. The batteries have held up fine. I agree Zippys aren't the greatest by any stretch, but at the price they are an extremely viable alternative and perfect for bashing with proper gearing. The only issue I've been having with them is one of my 4S packs has a cell which holds about 0.01v less than the rest. I'm pretty anal when it comes to balancing, and need the tolerance to be +-0.005V

[BrianG]

Originally Posted by pasan

...The only issue I've been having with them is one of my 4S packs has a cell which holds about 0.01v less than the rest. I'm pretty anal when it comes to balancing, and need the tolerance to be +-0.005V

Are you sure that is a real issue? Balancers are not 100% accurate either. Even components with 1% value tolerance can easily introduce enough variance to account for 0.01v. Heck, even dirty balance connectors can cause an erroneous reading. I would measure each cell with a multimeter to be sure.

And even if the cells are 0.01v off, that's nothing to worry about at all. Believe me, I'm pretty anal about having things properly matched. If you are worried that a cell could get above 4.2v because of this, just set your charger CC/CV threshold to 4.15v/cell, if it supports this feature. You lose VERY little runtime. Actually, I have my Xtrema set to this value for this very reason.

[shaunjohnson]

i like this thread a lot of good info on here abour ripple current and TVC.

yes overdrawing the batteries is REALLY bad...but upping the voltage and running 6s will increase the watts that can go in and out of the battery but can do this at lower amps, correct?

so running 6s zippys-H or 6s zippy flightmax SHOULD be alright.
if you do not gear it high then that also lowers amp draw...we gear our revo for 40mph max.
temps stay cold all round.

so riple current is silved by getting top quality batteries or changing the way you drive or cranking it up to 6s and gearing down (same watts of power...less amps).

will relay all this info to my fellow noobies (no i wont tell any "idiot forum" members about here LOL)

[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

[pasan]

Brian, I do measure my packs with my multimeter during and after charging. That's how I discovered the variance in voltage. I know it's probably nothing, but the pack in question has been doing this regularly for the past month. My charging setup is rather primitive, being just a Triton Jr with an Astro Blinky. I'm seriously considering investing in a Turnigy Accucel-6.

[BrianG]

Ok, what about the balancer tolerance? Does it balance the cell you measured as 0.01v difference? I know my blinky doesn't. The most accurate balancer I have is the LBA10 (it actually seems almost too sensitive).

For your level of "anal" (), I wonder if the FMA charger would be a better choice. Has a high power limit, balance charges, and also measures cell condition/quality. To do that last item, it must be quite accurate.

[squeeforever]

Originally Posted by pasan

Brian, I do measure my packs with my multimeter during and after charging. That's how I discovered the variance in voltage. I know it's probably nothing, but the pack in question has been doing this regularly for the past month. My charging setup is rather primitive, being just a Triton Jr with an Astro Blinky. I'm seriously considering investing in a Turnigy Accucel-6.

I think I would get the Icharger 1010B+. I've been reading there MUCH better than the Turnigy. Most of the cheap chargers at places like Hobbycity are VERY inaccurate on the voltage. The new 1010B+ and the 106 are better calibrated from the factory. For $190, you get a hell of a charger. 10S BALANCING charger with all kinds of features and stuff. Can't beat it.

[emaxxnitro]

at that price just get the fma cell pro 10s its a wail of a charger, for 190$ charges up to in our case 2c with a 10amp max output.
http://www.fmadirect.com/new_applica...0s_charger.htm