Turnigy LiFEPO4 packs - Page 7 - RC-Monster Forums

lincpimp · 11.23.2009, 02:37 PM

For 50 bucks a pair plus shipping you can hardly go wrong, half the price of ONE pack from the competition...

11.23.2009, 03:00 PM

I was wondering though if these were way out of balance like you hear about with some of the less expensive lipos. Also James when you get a chance to run them, please comment if you think of the claimed discharge rate is accurate.

suicideneil · 11.24.2009, 11:54 AM

Not way out of balance- as Sike stated, they come well balanced and maintain a good balance, within .003 volts after charging. They certainly arent reject cells like MA would like you to believe- thats called a smear tactic to make you mistrust them, and instead buy their insanely overpriced versions (that are more than likely to be the exact same cells/ from the same factory...). Have faith

11.24.2009, 12:39 PM

Neil, I totally agree with you, was looking for James' input as well as he knows his batteries. Plus his set is likely out of a different batch as well, so I thought if several people chimed in that have them it would be interesting. I plan on ordering me a set in the next few days, I just don't have the experience or ability to test them myself or I would try and add too.

I thought Himalaya really hit the nail on the head on page 4 talking about that the cells are graded, but if they were to far out of tolerance they would need to check the production line. I think this is an excellent point since MA claims they are "rejects". I remember in college I had Production/Operations/Management where this was discussed a lot. With many if not most products like batteries made there and sold around the world they have come a long way in terms of quality, they had too. And while we here focus on the batteries that apply to us as far as RC goes, they are in tons of products. Lap tops, cell phones, hand held video games, PDAs,........and so on. Anyway long story short, that reason given by MA just doesn't cut it any more in the global market place.

jpoprock · 01:30 PM

So, let me get some clarification about these packs... cuz I'm about to maybe buy two of them for my Emaxx w/ EVX2. These packs will be fine, maybe a bit slower than say a 5000mah 2s 40C Zippy, but they don't need balanced, and I won't need an LVC or battery alarm for them?

My Hyperion will charge them, so that's not a problem. I was just wondering if there was any REASON I should buy a couple of these over some Zippy Lipos... if not just to "try"? I'm sure I'll be happy with them though. it's not a matter of money really. It's more about, "Gee... maybe the slower speed will be ok in trade for convenience?" I don't find Lipos to be inconvenient though.

Another note.. i'll be running these and the lipos in snow.

Oh, and with Life packs... I can charge them super fast right? And I don't have to balance them. I charge my lipos in sync mode if running two of them. I won't have to do that with Life packs? Or does it matter?

suicideneil · 11.24.2009, 01:35 PM

LiFe cell = 3.7v fully charged vs Lipo cell = 4.2v fully charged- draw your speed comparisons from that info.

They do need balancing though- its just good practice + they come with balance taps attached anyway so...

The only real noticeable difference will be that you need a 2p setup to output the same amount of punch as a normal 1p lipo pack, hence people using 6s2p setups when Life/ A123 cells are envolved (comparable to a 5s lipo setup of the same mah (~4000-5000 25c)).

The biggest advantage really is the ability to charge them in ~15mins vs ~1hour for lipos, assuming you have a suitable charger..

jpoprock · 11.24.2009, 01:37 PM

One more thing.... I've read thru this thread...and it appears I should maybe dip them in silicone to waterproof them. They likely won't get "soaked" though.

I'm sorta of clueless when it comes to all of the "data speak" about charging, discharging, amps, etc... The one dude on here (sorry, can't recall the name!), monitors the crap out of his charge, and posts all kinds of info. I'm hoping that getting that geeky isn't need really... because I run my batteries until the LVC kicks on, or until I'm done, then I will almost always top them off when I decide to run again. I always balance them, and never mess with discharging or anything like that. I run them, charge them, run them charge them. That's it! I sometimes will look at my Hyperion to see what the resistance is, just for kicks.

So..... should I be doing something different? Or is ignorance bliss?

jpoprock · 02:24 PM

Neil, so basically if my EVX-2 can only handle Lipo's in 2p config, that rule doesn't necc apply with Life packs because it's all about voltage, not how many cells.

Be gentle, cuz I'm really trying here.. and i know it's been discussed 10zillion times already... so in the case of the EVX2, rather than running a 4s2p config with an LVC on the BEC side... I could run a 2s Life pack on the BEC side, and a 3s Life pack on the other, to acheive the same results ala 16.5v's/5s2p?

At KA's site... they are selling a two pack 2s 4500 set for the Emaxx... but that's like 13.2v's. Unless I'm wrong in my understanding of what you've told me. And I'm gonna have to measure my compartment, cuz that 3s Life pack might not fit.

Thanks! Didn't mean to turn this into a "how to". I think i get it now...

lincpimp · 11.24.2009, 02:28 PM

Not sure if the evx2 can handle 5s LiFe cells in series, that would be 18v fully charged...

I would go with a pair of the 2s2p 4500 packs. Plug them in like you would do with stick packs and go play. No need for a lvc, just stop when the performance dies off. It is a brushed truck, just leave it stock and enjoy it for what is is.

As for waterproofing the packs, dip them in plastidip, of use a small ziplock baggie. Unless you plan to submerge them in water, you really do not need them to be 100% waterproof.

I just checked the balance of the LiFe pack I have as I received it and it is almost perfect. I plan to get a setup together to run this, might be a week or so...

jpoprock · 11.24.2009, 03:37 PM

Quote:

Originally Posted by lincpimp

Not sure if the evx2 can handle 5s LiFe cells in series, that would be 18v fully charged...

Sorry. I was speaking of a 2s on one side, and a 3s on the other. Both 4500mah's to equal 5s.

So now what say you about that?

lincpimp · 11.24.2009, 03:59 PM

Quote:

Originally Posted by jpoprock

Sorry. I was speaking of a 2s on one side, and a 3s on the other. Both 4500mah's to equal 5s.

So now what say you about that?

I understand that you planned to run a 2s on the bec side, and a 3s on the non bec side. I was just not sure if the evx2 can handle that...

If it can handle it you should be good to go.

sikeston34m · 11:35 PM

Just a little update here.

After running 5 or so cycles through the MM Pro in the e maxx running a HV4400 with sinter rotor/5mm shaft, it was time to move them to my E Revo.

My E Revo is setup with:

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

This is more of an amp hog than the E maxx setup.

The packs handle the E Revo just fine. They have alot of punch.

I've ran them in the E Revo 4 times now. Two of those times were both in the same hour today.

20 amp charge rate.

They come out of the E Revo about 100 degrees. Still not bad, but this does show they are being pushed harder.

himalaya · 11.29.2009, 05:49 AM

Quote:

Originally Posted by jpoprock

Sorry. I was speaking of a 2s on one side, and a 3s on the other. Both 4500mah's to equal 5s.

So now what say you about that?

A123s have huge voltage drop under load, 2.5V/cell is pretty typical. The BEC has no way to provide 6V output with only 5V input.

Maciolus · 12.01.2009, 04:08 PM

Do you know exact size of single cell (4500mAh pack is 2P)? I am wondering if it is possible to make saddle pack for 1:10 buggy.

lutach · 12.01.2009, 05:38 PM

Quote:

Originally Posted by Maciolus

Do you know exact size of single cell (4500mAh pack is 2P)? I am wondering if it is possible to make saddle pack for 1:10 buggy.

I have attached a picture of what the cell looks like, but you can have it with the leads like the other picture of the 5000mAh. The size of the 2250 cell is: 9mm X 34mm X 104. I have other pictures of the other cells available if you or anyone else would like to see.