Are Zippy Lipos safe with a Castle MMM Speedy?

[squeeforever]

Originally Posted by 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

The 1010B+ is also 10A and seems to have more features.

[fastbaja5b]

Originally Posted by 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...

Ok so I understand this yet here in Australia they are being told that ESC's are blowing as they are running the 20t pinion in a flux and not the 25t for 6s? I mean WTF? By your logic I should go down to a 14-15 pinion to lower the amps, by their logic I'll blow everything up!

What is increasingly frustrating is the lack of response to my direct questions on this matter by email to castle creations, there are more and more savage flux - ESC go boom - videos coming onto You Tube, yet I can't get any clarification on this matter, just a lot of theorising.

[lincpimp]

Originally Posted by fastbaja5b

Ok so I understand this yet here in Australia they are being told that ESC's are blowing as they are running the 20t pinion in a flux and not the 25t for 6s? I mean WTF? By your logic I should go down to a 14-15 pinion to lower the amps, by their logic I'll blow everything up!

What is increasingly frustrating is the lack of response to my direct questions on this matter by email to castle creations, there are more and more savage flux - ESC go boom - videos coming onto You Tube, yet I can't get any clarification on this matter, just a lot of theorising.

You can run smaller pinions, but you may find the motor undergeared, and it may run warm because of that. Otherwise it should be fine. If I were to buy a savage flux I would run 5s lipo and regear it to do around 42-45mph. That would most likely mean dropping 2 teeth on the pinion to a 23t. You can run it however you want, just take temps regularly and you will see what is not working. If you plan to run 6s, I would gear down a few teeth. Then keep an eye on the batts and if they get too hot you will need to drop a few more teeth. A MT on 6s that is geared for more than 55mph is generally a handful. That is why most of us gear for 45mph or so.

[fastbaja5b]

But if you go by this thread:

http://www.ausrc.com/forum/showthread.php?t=15868

He's being told his esc blew as he ran the 20t pinion (stock gearing) and not the 25t pinion (optional included)

so doesn't that contradict what you are saying?

By your logic he should have gone down to a 12/13 perhaps, by theirs, the smaller pinion is what fried the esc

[skellyo]

Originally Posted by lincpimp

You can run smaller pinions, but you may find the motor undergeared, and it may run warm because of that. Otherwise it should be fine. If I were to buy a savage flux I would run 5s lipo and regear it to do around 42-45mph. That would most likely mean dropping 2 teeth on the pinion to a 23t. You can run it however you want, just take temps regularly and you will see what is not working. If you plan to run 6s, I would gear down a few teeth. Then keep an eye on the batts and if they get too hot you will need to drop a few more teeth. A MT on 6s that is geared for more than 55mph is generally a handful. That is why most of us gear for 45mph or so.

The Flux already does 41mph on 4S with a 20T pinion and a little tire ballooning. Going to 5S, you'll want to drop 2T-3T from the 20T to get back down in the mid 40mph range if you account for ballooning.

[fastbaja5b]

even the flux manual says on 6s use a higher pinion than on 4s

WTF?

[lincpimp]

Originally Posted by fastbaja5b

But if you go by this thread:

http://www.ausrc.com/forum/showthread.php?t=15868

He's being told his esc blew as he ran the 20t pinion (stock gearing) and not the 25t pinion (optional included)

so doesn't that contradict what you are saying?

By your logic he should have gone down to a 12/13 perhaps, by theirs, the smaller pinion is what fried the esc

If the smaller pinion caused themotor to be undergeared it would heat up. Not sure if that would affect the esc enough to cause it to pop...

Originally Posted by skellyo

The Flux already does 41mph on 4S with a 20T pinion and a little tire ballooning. Going to 5S, you'll want to drop 2T-3T from the 20T to get back down in the mid 40mph range if you account for ballooning.

Ahh, I though the 25 was stock. Must have misread a previous post. So why do they include the 25t pinion? So you can gear up if you plan to run nimhs? Does not make much sense to me...

Originally Posted by fastbaja5b

even the flux manual says on 6s use a higher pinion than on 4s

WTF?

Can you link me to a pdf or something like that for that portion of the manual...

Even with the 20t pinon the truck is doing 55+ mph on 6s lipo. That is plenty of load on the motor. A 25t would go past 65mph. I see no reason not to run the 20t pinion with 6s, other than 55mph is a bit much for most bashing situations, and some lipos. A 16t pinion on 6s would be much more manageable, or a 19t pinion on 5s...

[fastbaja5b]

Here is a link to where you can download the manual

http://www.hpiracing.com/kitinfo/100646/

Even Traxxas tell you to gear up when going from a 2s to a 3s Lipo

Doesn't this all sort of contradict our conventional logic of gearing down on more cells to pull less amps and therefore less heat?

[skellyo]

Originally Posted by fastbaja5b

Even Traxxas tell you to gear up when going from a 2s to a 3s Lipo

Nope, they actually recommend you gear down for 6S. That's the opposite of the HPI manual. Here's the BL E-Revo gearing chart:
http://www.traxxas.com/PDF-Library/5...anual_addm.pdf

[fastbaja5b]

But take a look at the manuals for the Stampede, Rustler and Bandit VXL's!

And that chart tells you to gear down from stock for a 4s, but I don't see any mention of 6s on there

[pasan]

Originally Posted by 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.

I think the Blinky somehow can't quite bring the rest of the cells down to that voltage and keep them there. I usually charge while balancing. I too think a balance charger is best but I'd like a charger which actually does something more than a balance, i.e. by pushing extra juice to a weak cell to bring it up to par rather than bringing the others to voltage of the weakest cell, which IMO is very inefficient.

[lincpimp]

Originally Posted by pasan

I think the Blinky somehow can't quite bring the rest of the cells down to that voltage and keep them there. I usually charge while balancing. I too think a balance charger is best but I'd like a charger which actually does something more than a balance, i.e. by pushing extra juice to a weak cell to bring it up to par rather than bringing the others to voltage of the weakest cell, which IMO is very inefficient.

Only way to get what you ask is to use a seperate charger for each cell. Any charger on the market charges the entire pack of cells in series. Only way to equalize them is to put a load on the higher cells and bleed off some juice. If you had a seperate charge curcuit for each cell the balancer would not be needed, as each cell would go thru the cc/cv cycle on its own terms, so to speak.

[lincpimp]

Originally Posted by fastbaja5b

But take a look at the manuals for the Stampede, Rustler and Bandit VXL's!

And that chart tells you to gear down from stock for a 4s, but I don't see any mention of 6s on there

A vxl esc cannot do 4s, IIRC... 3s max.

[pasan]

Originally Posted by lincpimp

A vxl esc cannot do 4s, IIRC... 3s max.

Some people have reported running a VXL on 4S and 12 cells with the BEC disabled and cooling fan. But of course that would be voiding Traxxas warranty.

[hoovhartid]

Originally Posted by lincpimp

So why do they include the 25t pinion? So you can gear up if you plan to run nimhs? Does not make much sense to me...

I wonder if the problem is the tires?

maybe they expect you to use phaltline tires with the 25t and the MT size ones with the 20t?