Any particular reason for needing a LiFePo4? I don't buy anything from MA just on principle.

Safety is the main reason.

LiFe chemistry doesn't go into thermal runaway. The packs can still catch fire if they overheat (overcharging), but won't keep burning like magnesium and lipo does.

Precisely, safety. My Mini is what usually gets put in the boot for vacations, in the family ride thats behind where my 7 month old sits, in my "bunky" that's up against an LPG tank.

Neither are areas you want unstable packs. Also babys get into things, chew on things etc, Lipo pack + teeth?

As much as I enjoy this hobby, Safety has to be my #1 thing now, that's why the Savage Flux runs on Lifepo4 and why I want the Mini to as well.

Fastbaja5b, I'm in the same boat in terms of safety being a big concern with a small child getting into everything along with the fact I'm new to rc. What kind of setup are you using for the flux? I have the truck NIB waiting to be run when I can get some more ideas as to batteries, charger, any tray mods, run time, etc. Are you generally satisfied running liFe? Thanks.

So guys... what can I expect from two 2s 4500mah Life Packs by Turnigy if sticking them in my Summit or Emaxx for winter driving? Both trucks have a single Titan 775 and the EVX2 ESC's.

I understand that Lipos don't like cold weather, and it's COLD here. But I can wrap them in a "blankie" to keep them warm if need be, since they are so thin.

What would be my run time and torq expectations when running the Life packs vs 2s 30C Turnigys, vs a 7 cell NiMH pack that is comparable? If the Life packs I'm looking at really won't give me good run times, or will be wicked slow, than I'll just stick w/ the Lipos and take my chances. Either pack is about the same price. I'm wanting runtimes for winter driving, because I don't want to have to mess with coming in and recharging all the time. Cuz once I come in from the cold, I won't want to go back out! And really.... 30min of snow driving is long enuff for me to get my RC fix for the day anyway.

Thanks!
jason

LiFes should be just fine. With a brushed motor I would expect that you're going to get the same power, they don't put enough load on them to make a difference. I don't think the Titan pulls enough amps to keep the batteries warm on their own, so I guess that it's possible that they could get too cold even when cozied up in the Summitt's battery compartments. Might want to go with the LiFe packs just to be safe, plus you can charge them faster if you need to get your fix a little more often (if not in the Winter, you can sure use this in the Summer).

Thanks. are the run times as long as an equivalent Lipo, or more like a NiMH pack?

Well fooey... HK is now out of stock! Maybe next order...

I'd guess you should get similar run times to a lipo. The discharge characteristics of a LiFe pack are more like a NiMH though, they stay pretty solid with some voltage drop across the run but at the end they straight-up dump and you KNOW it's time to stop.

Thanks for the info. I'll probl pick up a couple packs on my next order, which could be a while. But there are some things from there that I'd like to pickup when they come back in stock.

Jason

Just got my order in for a pair of them before they went out of stock. Planning on using them in my TC3 indoors this winter.

How does charging the packs at high rates affect the pack's life? I have heard that the larger charge rates can cut the packs life by half or more, but that 2-3C is pretty safe.

Wikipedia says that rapid charging will shorten the lifespan when compared to trickle charging, but it doesn't say anything defining "rapid" as far a C values, and doesn't have any source cited.

I'm probably going to charge my 4500mah packs at 9A. I'll be happy with cutting charge time in half compared to my lipos, and hopefully with swapping the two packs back and forth in my conservatively setup TC3 I will have little, or possibly no downtime in between runs.

I don't know if it's true or not. I talk with people that makes way more powerful batteries and the current one they have is capable of 400C continuous and can be charged in 2 minutes at 150A. Now they say fast charging may impact life of the cell, but they have done so far over 3000 cycles and this particular cell still have over 80% of its capacity. I just wish I could get my hands on a few :lol:.

I do believe there are advances in battery technology that are still in the beta phase testing phase.

I've had a few talks with one individual about a "AA" size Lifepo4 cell that the manufacturer claims a 1600mah capacity on.

This energy density is much greater than the former 450-500mah "AA" sized Lifepo4 sized cell.

If they can get the energy density this good, regular lipo chemistry may become a thing of the past.

Hmm, 3000 cycles and still holding 80% capacity. That would make a great 1:1 car battery for an all electric. 8 years of lifespan... If we were making electricity with nuclear (or fisson) it would be the way to go. Coal fired power is not really optimum for electric cars...

There are 2 types of LiFe battery. One is the Power cell that has less capacity, but offers higher C rating. The other is the Energy cell that has more capacity, but offers very low C rating.

They are being used in Tanks, Fighter jets, Directed energy weapons, Electromagnetic launchers, Light sabers and so forth. I'm trying to get a few to test it for my 1:1 race car and also to see if it'll handle my 1.5T motor :lol:.

Aren't those the Ultra Capacitors that EESTOR has been working on for a few years now? They are working on those Capacitors for a company named ZENN Motors who make electric cars up here in Canada. (but they can't sell them in Canada :no: Stupid Government). Judging by an article I read about the new crop of ZENN cars for 2010, I think they might have achieved their goal.

Here's a quote from the ZENN Motors website.
''The ZENNergy™ drivetrain solution promises to deliver energy storage packs that are
• one-tenth the weight and mass of lead acid batteries,
• capable of one million-plus cycles,
• able to be fully recharged faster than any electrochemical
*battery and deliver superior performance in extreme
*operating temperatures
• safe
• cost effective – lower cost than current Lithium Ion
*battery technology''

No, they are actual batteries being used by various military clients. I really don't know how ZENN will actually produce those as it seems a bit of science fiction to be honest. If they have such technology, it'll be worth a huge amount of money. It seems more like a scheme to get dumb investors to throw more money at them. Look at the companies getting grants from the US Government to make electric and/or hybrid vehicles. If it's actually a capacitor, it will be like any other capacitor we currently know of. I know of a company in Canada that actually has a few working capacitors and some have been used in 1:1 racing application. I plan to use those in my 1:1 race car as well. I can come up with juicy ideas as well and throw it in a website to milk investors for money, but why should I do that. The people I've currently spoken with about my 1:1 race car don't actually think its doable, but I know it is as the technology is already available now. I really should make some BS story, they'll probably fall for that.

Choose not to believe in it, that is your prerogative. The science fiction in question is called EESU from EEStore, which centers around a core of aluminum coated barium titanate powder immersed in a polyethylene terephthalate plastic matrix. They filed for a bunch of patents that have recently been granted regarding this new technology.

Anyone can make a patent even for things that can never be made in our life time. I can go in there and look through the EEStore, BASF, Northrop Grumman, Philips and others alike and come up with my own. They also failed to produce a prototype to showcase the technology to some big names out there. ZENN is just dumping money into EEStore just incase they do make it work so they can make a huge amount of money with the technology. Risk capital or venture if you ask me. If they had something to show for, you would see some real investors going in and basically taking over the technology.

Yeah, that's what I thought too. But don't forget about the variables found if you take the resistance of the base ohmage and multiply by the sum of your top speed and heat index, you can then decide to what degree you need to set the hyper-threading mechanism inside the compression chamber of cell #1, and ONLY cell #1!!!

However, this is best realized in a 1:3 application. You were speaking of a 1:1, making the scenario moot really. But in either event, you should be able to finally arm the flux capacitor properly.

Hope this helps!

Steven Hawking

I like Steven Hawkins. It would be awesome to sit down and have a chat with him.

Heck yeah! But what on Earth would you talk about? He's one of the greatest living minds of our time.

"So Steven... Have you ever spelled the "F" word on your little Speak and Spell there?"

Or better yet:

"Why do people buy MA batteries?"

Or my favorite:

"Which brand of Lipos are the best?"

Many things. A few new theories that I have in my head driving me crazy. His theories and what he thinks about other's theories. How the hell can I create a light saber. What are his thoughts on the world today. Common things like that you know.

I'm just teasing u guys for being way smarter than me. The conversation turned "tech talk for scientists" and I had to laff at how over my head it was.

However... If I knew I was going to meet him and get to talk, I'd come prepared, trust me. I watch a lot of show about the universe, supernova's, etc. I even read one of his books!

I did sorta follow what u were talking about to a degree. It's probl all Alien in origin anyway!

I hope u eventually get the answers yer lookin for man...

:lol:. Most of the guys in this forum are smarter then me. I would love to see the higher LiFe (Lithium in general) technology find its way into our hobby. If there's another technology better, it'll sure make it better as well for more options to have fun :lol:.

I think the British Columbia government has or will change the automobile act/regulations so cars like the zenn Could be driven on the Street of B.C..

I heard today from an engineer that battery's abilities (e.g. capacity) are doubling every two years, so it wouldn't be a problem for the car he's designing now to reach 500 km range in 2012 or so.

I was thinking about the last four years with LiPos and that good 30C cells have been around for about two years now... and most importantly, that I don't see a big increase in energy density. So my conclusion is: This is BS. Such an improvement could only come from a new technology, but I don't see it happening.

Such a car could've been done already. The technology has been available since early 2000. I sent my idea to a few of my client's to give me a rough idea of how far the vehicles I have in mind would travel. They said it would be able to go from New York to California and probably back. This was without one of the key components of my design. The new technology we read about mainly comes from people trying to get the most money for them. Look at A123, they have yet to show a profit, have patent issues, place to manufacture them and only 2 commercially available cells which are all 30C. I can get more cells done with a higher C technology and I'll be trying 2 cells, but mainly for our hobby use. I will also rub them in the A123 investors to see what they'll say.

An electirc car is what I've been dreaming for years. Forget the inter-transition Hybrid vehicles, it's a mule carring its both parent horse and dunkey in it's cart. They are not likely to have "next generation hybrid":mdr:

I am planning to convert my VW Bora(called Jetta A4 in America) to electric when someday it's engine fails if there's still no decent electric car available. Any good 1/1 conversion kit vendors you guys recommend?

I'd like to do that with a SMART car since they're so small and light. Once I take out the engine, tranny, fuel tank, and other assorted crap, it would probably be light enough to either make a hole in the floor a la Flinstones, or slap a set of bike pedals on it. :smile:

So........ how about those Turnigy LiFePo4 packs that this thread is supposed to be about? Gotta go pick mine up from the post office tomorrow, then I'll run em in my touring car and report back.

Got my pair of Turnigy LiFe packs today (2S 4500mah). Pack 1 had cell voltages of 3.364V and 3.364V, pack 2 had 3.364V and 3.362V. Of course in my infinite wisdom I forgot that I don't have any more Dean's connectors laying around, so I won't be able to test the cells for a few more days.

I'll be running them in my TC with a Castle 4600kv and geared for about 35mph. The next thing on my list is to get an EagleTree and see how these packs hold out under a load.

Great!

Please keep us posted Simplechamp. I think you'll be pleased with the results.

I would love to see some Graphs for these packs.

Lutach, can you tell me more about your idea? I have no idea what you mean.

I'm currently designing some parts to convert this car: http://www.amzracing.ch/amz/files/amz1064.jpg
Well, it's not really a conversion, we're building a new monocoque and everything. With LiPo of course. We can discuss it here: http://rc-monster.com/forum/showthread.php?t=17955

No doubt. I have to see how I make it through the holidays money-wise, but an EagleTree is next on my list.

I posted something in that thread. So this one can be on track again.

I said I would love to see some graphs on these packs. Well since I acquired a Data Logger, here it is:

This run is 4S 4500mah Turnigy Lifepo4 in an E Revo with the following setup:

HVmaxx 4400 running a sintered rotor w/5mm shaft
gearing is 14/52 using Mod 1 gears
MM Pro

It will point the nose to the air almost at will and will flip over backwards with good traction.

Still better than the A123 cells.

Looks like about 2.75 volts per cell under a 108 amp load. Check this out.

http://i160.photobucket.com/albums/t...po4Turnigy.jpg