Are Zippy Lipos safe with a Castle MMM Speedy?

[fastbaja5b]

No I mean the e-revo post refers to a 4s set up using the MMM set up, what I meant was the VXL Manuals saying gear up from 2s to 3s (same principle which contradicts what is said here re - gearing down on more volts to lower temps)

example:



But I know a lot of people run a VXL on stock gearing with 3s and it's fine.

What we are being told here on the Savage Flux is essentially the 20t Flux pinion is for 4s, we MUST run the 25t pinion on 6s otherwise it could blow the ESC, it's happened on a Maxcramps pack http://www.ausrc.com/forum/showthread.php?t=15868 and apparantly on a Zippy as well http://www.rctech.net/forum/electric...os-smoked.html . (Could just be a faulty component but in the case of the Flux blowing they are pointing the finger at people running the 20t pinion and not the 25t)

Now doesn't that sort of contradict the whole premise of gear down, volt up = cooler system???

[sikeston34m]

Originally Posted by fastbaja5b

example:

With this chart, please keep in mind the discharge capabilities of the batteries.

Nimh can NOT and will NOT carry a huge amp load. Top of the line Nimh packs just won't keep up with what quality lipos can do.

[skellyo]

Originally Posted by fastbaja5b

What we are being told here on the Savage Flux is essentially the 20t Flux pinion is for 4s, we MUST run the 25t pinion on 6s otherwise it could blow the ESC, it's happened on a Maxcramps pack http://www.ausrc.com/forum/showthread.php?t=15868 and apparantly on a Zippy as well http://www.rctech.net/forum/electric...os-smoked.html . (Could just be a faulty component but in the case of the Flux blowing they are pointing the finger at people running the 20t pinion and not the 25t)

Now doesn't that sort of contradict the whole premise of gear down, volt up = cooler system???

This is a good question for Patrick to see what his thoughts are. I think most of us here agree that going to a smaller pinion on 6S is the more intelligent thing to do. Perhaps the HPI folks just don't have enough BL knowledge to understand that?

[johnrobholmes]

It is a typo in the manual. It happens, and this time it will cost HPI a ton of money.

[RC-Monster Mike]

Originally Posted by johnrobholmes

It is a typo in the manual. It happens, and this time it will cost HPI a ton of money.

My thoughts exactly. :)

[lincpimp]

Originally Posted by RC-Monster Mike

My thoughts exactly. :)

+1 on this... At least that is what I got when I read it.

[Arct1k]

Actually I'm not 100% sure as they do advertise it IIRC as 62mph out the box...

I think there should be some caveats to this though...

[lincpimp]

Originally Posted by Arct1k

Actually I'm not 100% sure as they do advertise it IIRC as 62mph out the box...

I think there should be some caveats to this though...

They list 62mph with the included 25t pinion and phatlines...

[skellyo]

Originally Posted by Arct1k

Actually I'm not 100% sure as they do advertise it IIRC as 62mph out the box...

I think there should be some caveats to this though...

Yes, there should be. For instance, running the stock tires on 6S with the 25T pinion should be a no-no.

Originally Posted by lincpimp

They list 62mph with the included 25t pinion and phatlines...

Yep, and the speed calc comes up with 62mph for it with a 25T pinion, 6S and Phaltlines, so it's probably pretty close to accurate.

[RC-Monster Mike]

The manual DOES say that high quality batteries are required and lack thereof can result in failure. The gearing chart is off base, though.

[bruce750i]

IMO The charts are telling you how to get to the listed speeds not how to have a cool running system.

[vbxt]

Originally Posted by lincpimp

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.

I think that this charger from Hobby City might do what you are talking about.
http://www.hobbycity.com/hobbycity/s...Charge_Capable

I have one, and it appears to charge each cell (up to 4) independently. There are 4 LEDs that indicate the charge status, and they switch from red to green at the end of the charge cycle at different times as each cell is fully charged.

I have no complaints about this charger other that the slow charge rates.

edit: I just remembered that this charger also does not seem to have any problems with over-discharged packs. I was discharging a SMC 5000 mah 2S Lipo with a light bulb and forgot about it. It was reading 0.0 volts on my multimeter. I hooked it up to this charger, it fully charged it, and it still works perfectly to this day. It may all be in my head, but I think that it works better than before!

[lincpimp]

Originally Posted by vbxt

I think that this charger from Hobby City might do what you are talking about.
http://www.hobbycity.com/hobbycity/s...Charge_Capable

I have one, and it appears to charge each cell (up to 4) independently. There are 4 LEDs that indicate the charge status, and they switch from red to green at the end of the charge cycle at different times as each cell is fully charged.

I have no complaints about this charger other that the slow charge rates.

edit: I just remembered that this charger also does not seem to have any problems with over-discharged packs. I was discharging a SMC 5000 mah 2S Lipo with a light bulb and forgot about it. It was reading 0.0 volts on my multimeter. I hooked it up to this charger, it fully charged it, and it still works perfectly to this day. It may all be in my head, but I think that it works better than before!

Interesting, I would like to get one of these and take it apart... Might be a good product for me as I always seem to be repairing packs and balancing cells individually...

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.

Originally Posted by vbxt

I think that this charger from Hobby City might do what you are talking about.
http://www.hobbycity.com/hobbycity/s...Charge_Capable

I have one, and it appears to charge each cell (up to 4) independently. There are 4 LEDs that indicate the charge status, and they switch from red to green at the end of the charge cycle at different times as each cell is fully charged.

I have no complaints about this charger other that the slow charge rates.

edit: I just remembered that this charger also does not seem to have any problems with over-discharged packs. I was discharging a SMC 5000 mah 2S Lipo with a light bulb and forgot about it. It was reading 0.0 volts on my multimeter. I hooked it up to this charger, it fully charged it, and it still works perfectly to this day. It may all be in my head, but I think that it works better than before!

Cool charger functions but wont work if you have a pair of 3S batteries and its going to take a LONG time to charge at 2amps max.