Turnigy LiFEPO4 packs
 

Might aswell post here.:intello:

http://www.hobbyking.com/hobbyking/s...idCategory=218

What LVC do you run on a 4S pack in MMM? How much of a difference would I notice when using 4S lipo or life? For ERBE. (3S doesn't fit)

IIRC, A123s LVC around 2.5v. But really, you will notice the loss of power at the end of the cycle so an LVC is not really needed. 4s LiFe is gonna be 13.2v (3.3v/cell), whereas 4s lipo is 14.8v, so right there you will lose some speed. And if you gear up too much to compensate, the current will go up, which might exceed the pack's capacity. It says 30C (135A), but I'd like to see some ET graphs before I believe that.

Brian,

What do you think MA will do when more people find those packs? I was going to buy some to make it 1P (2,250mAh) for my applications, but like you, I want to see some graphs on them as well.

Are they sensitive to wet conditions? (snow) Probably gonna order a pair tomorrow.

Most batteries will not perform very well in cold weather. There could be a very large voltage drop and it could hurt how they perform and if drained too far, you might damage them.

With the A123's I ran, the discharge rate seemed to me to be as good as the Lipo's - but that was just by seat of the pants on my part. They ran well with my Novak, and even a little better with the MMM/Castle. However, when run on a stock E-Revo, they did not seem to perform as well as the Nimh batt's my in laws had.

Pre-warm them in your pockets/indoors to around 100*F, then dash outside to use them; the longer you wait, the more they will cool down- dont store them in a gargage or shed either, store them in your nice warm bedroom.

Anyway, I would use 2 of those packs in series, say 6s2p to replace a 5s lipo, or 4s2p to replace a 3s lipo, or 5s2p (3s + 2s packs) to replace a 4s lipo.

But... $120 vs $25 (2s2p 4500packs, direct comparison)= MA are toast- spread the word brothers! :lol:

I don't know about you guys, but I smell a bunch of BS coming from MA about how their cell chemistry is superior, pack construction, "factory fresh, made to order" as if they were a sandwich...

MA packs may be using the same cells, but maybe they are weeding out the "bad" ones/matched better? Remember, I said "maybe". :wink:

:lol:....I know one place that makes similar cells, but the problem is the MOQ they have. The word will spread fast and MA better have a good back up plan to explain how different their pack is :lol:.

Question is, could they really be going through so many packs that the cells they use don't actually sit on a shelf? How many of you have actually seen the "Factory"? I know Castle Creations makes their own ESC and we've seen pictures of the factory. When MA had a somewhat decent price, yes I bought 2 packs, but almost paid the real price.

A123 or similar soft pack LiFe are good 10C ~14C cells if comparing voltage holding capability with LiPos. They surely can be 30C discharged, if you don't care about how much voltage under load left and how hot the pack gets.

I wonder how those softpacks really compare to A123's.
Fresh A123's can discharge at 36C cont. They are good up to 160F or so. Voltage drop is very high, but you use the Amps to your advantage rather than the Voltage like in lipo's.

It's probably time for me to buy a data logger.

I have some of the 2S2P packs on their way and should be here the first part of next week.

Many of the questions you guys are pondering, I've been asking myself too.

I've ran A123 packs before and wasn't really impressed with them, due to the extreme voltage drop under a load. Lipos are famous for holding the voltage high during discharge.

I wonder if the flat poly form of the Lifepo4 will hold loaded voltage better than the cylindrical form?

In comparing the cylindrical form to the flat form, won't surface area of the anode and cathode material have a big impact on performance?

It stands to reason the flat form should be superior.

I will do side by side run tests to compare the 4S Lifepo4 to 4S Lipo.

4S 30C 5000mah Turnigy Lipo versus 4S 30C 4500mah Turnigy Lifepo4

My testing will be done with an E Revo.

MMM ESC and a Medusa 36-60-1500kv geared 22/40 using Mod 1 gears.

I want to see the differences in performance with no changes to the setup.

Then I want to alter gearing to compensate for the greater voltage drop of the Lifepo4 cells. I may even swap the 1500kv motor out for a 36-60-2000kv version.

I can either change the gearing, change the kv of the motor, or both to make up the difference.

I deal with the voltage drop, by going to a higher kv motor, or adding another cell with everything being the same.
Voltage drop is higher at the beginning, but once the pack warms up a bit(30 seconds or so) the voltage drop is less. Amp output is the same though.

I'm wondering how the CC Neu 2650kv motor would do paired with 4S Lifepo4 packs?

Several have said they weren't comfortable with how warm it runs on 4S Lipo.

Hmmmm..........I smell a sweet spot. LOL

I ran 2s2p A123 in my GTP with the 4000kv hacker motor and RX8. Everything got pretty warm.

So if I buy 5 of the hobbycity packs I should get at least 2 good cells for the 125 that MA is chargeing. Anything more than that is grvey at that point.

Just more proof of the MA scam. Seriuosly... What they are doing should be illegal.:bad:

Ok folks...It's official, MA said those are factory rejects. What I don't get is the only cells I had that failed were from MA. So who's selling rejects or low (extremely low) quality cells here?

Where did they say that Lutach?

http://www.rcgroups.com/forums/showthread.php?t=1141672

(Mike, sorry for posting another forum's link)

:whistle: Typical!

I'm surprised he didn't say "It wouldn't be fair to pick and choose from your questions."

Even though your question was the only one asked. :rofl:

He doesn't know where or how much, but yet is quick to call them rejects.

We'll see about that! :yes:

I will post back results and experiences once testing of these new packs is underway.

My E Revo spikes pretty hard when going WOT from a standing stop.

I remember putting in 5S 5000mah Lipo without changing the gearing. I ran it for a little bit and it just stopped. It blew one of the solder traces off the board on the 3S pack. I was able to repair that and it works like new again.

This was with Turnigy 5S 20C 5000mah. :sarcastic:

Turnigy lipos are like kit lipos- you may need to do some work yourself to finish them off, but after that they are 100% ready to go (barring any DOA cells). :lol:

There is a narrow spot in the solder trace on the 3S packs. It actually behaves like a fuse.

I'm sure the 5S setup was being over amped as they were being pushed hard! :oops:

I wonder if that "spot" is intentional?

As far as I know, all batteries are just thin films stacked, no matter if they're arranged in a cylindrical or a prismatic case or just wrapped in aluminium foil. But of course, the one with a hard shell will be heavier for the same performance.

WOW look at what someone just posted in there. Both funny and sick, ok very sick

Lol Maxamps locked the thread

so... what was posted? I missed it

stupid swears and insults at maxamps and a picture of 2 guys ontop of eachother and the words "this is jason taking care of buisness"

It's to bad that was posted as the more exposure MA receives on the obscene prices they charge, the better off the uneducated buyers are.

Well, unfortunately, it turned into a "He Said - She Said" debate instead of a data comparison between the two types of packs. Both "sides" were somewhat guilty of turning it into that.

If you had several MA Lipos that failed, it really has no bearing on the quality or validity of these particular packs. He did make a good point on pricing - if you don't like it, don't buy it. Their pricing is compatible with A123's pricing, and I have yet to see many forums filled with A123 bashing due to the pricing.

I for one have no doubt that the Asian built packs are factory rejects. Does that mean that they wont perform as well, maybe not - maybe so. Until there is long term testing, no one will know. Even if you were to have both packs brand new, they may perform as well right off the bat, but a factory "second" could start to show its deficiency down the road as it may "age" faster....

I am not a MA fan, and choose to not pay for what I percieve to be a product that is not as good as equivelently priced packs. But, I also wont tell someone that they wasted their money on them.

If MA couldn't show proof like Castle did of their factory, then how do we pay for what they say? It sounds like MA is just a chop shop that buys the packs assembled from Asia. They claim they build the packs here, but where's the proof. My Dodge RAM 1500 4.9L used to get 50mpg city and 100mpg highway. I have more money than Warren Buffett and Bill Gates combined. I'm not from Brasil. I have a Atomic Battery and a few vehicles have been left on full throttle for months now running a super test, the motors are spinning at 3,000,000rpm and the ESC is putting out 1000A in a tiny packs half the size of a Tekin R1/RS ESC. Speed is unknown, but it looks like 2,000mph. Awesome stuff you know. My teeth were pulled out in favor of diamond ones and I can bite through basically anything. I also have a cure for all the darn viruses and diseases. I'm a great speller without the need of a spelling tool. Also, 1+1=11.

lol, pretty big claims there. Some could be true I suppose. Speed could be 2000mph...in space. The spelling part could easily be true. But 1+1=10 (in binary). :smile:

lol. Forgot that part, yes, the vehicles are in a vaccum (Edit: did I spell veccum correct, darn spelling program just ran out of my laptop) chamber I made out of clear paper, strong stuff. Got some crazy things going here, so here's a link..........>>>>>>>>>>right here>>>>>>>>>>>see it>>>>>>>>>>>>>it's there I tell you>>>>>>>>>>click here.

lol, it's "vacuum". And no, I don't use spell-checkers. :wink:

Cool, thanks for the correction. Did you see the stuff in the link. Everything I said is true :yes:. I'm wearing my spec ops super strong suit now and will test if by standing in front of a tank's barrel. This paper thin material will stop anything and is supper flexible. I was also able to make a device that stops light and I should be able to make a light saber soon. I have been chewing a gum for the past few months now and it supplies me with everything needed to maintain a balanced diet. Have you seen the hair thin wire that pushes unlimited AMPs through it? Crap, my car just floated away, I forgot to turn the anti gravity module off.

You must in marketing. :smile:

This is not lutach, this is his clone. He made a few of us fairly easy. He should be back soon. He said he went to get blasted by his home made tank. Cool tank btw, it turns into a back pack for great mobility.

Ooohhhh! Our very own walking talking 15 axis NC machine....!

Good stuff and true :lol:.