Silicone, and lots of it!

Another player in the Life cells, but lets see if the S boys will go MA style on prices: http://www.redrc.net/2009/11/speed-p...of-life-packs/. They offer the choices I mentioned before. Looks like MA is lacking behind and have they gone a bit quiet? I'll be posting this at similar threads in here, so in advanced.....SORRY FOR SPAMMING.

SPAMMER! The S boys are most likely gonna match MA in price. I'll chill with my old school A123's untill the dust settles.

Where's that spammer....He should be banned :lol:.

Ok, so I got my turnigy 2s2p pack in today. Looks good, but i will give it a test in something, maybe a novak gtb with a 3.5 in a 10th 2wd buggy? That should put a load on it, geared for 60 or so...

That's a good test bed for it.

I think you'll see, they don't mind a big amp load at all.

My 2S2P packs went through some more testing today.

This time in an E maxx using a Novak HV Motor powered by a MM Pro.

The MM Pro is smooooooooth in sensored mode.

What I did different with testing was:

Using an AUTOMOTIVE type charger, which yields a 14.5 volt charge cutoff, I recharged the packs in series, at 20 amps!

The entire recharge took less than 20 minutes! I did monitor cell voltage with a meter while recharging.

They didn't mind this treatment at all. The packs were cold when the charge cycle started, and cold when it was done.

I was tempted to kick the charger up to 40 amps. Hmmm.......should I try it?

40 amps would be about a 9C charge rate.

go for it

I just took the E maxx out for another run a few minutes ago.

Didn't bother charging it up, since it was still partially charged from the last time.

About 10 or 12 minutes of running had it on the LVC.

I then hooked it up to the Automotive Charger again, only this time, I couldn't resist.

Bumped it up to 40 amp charge rate! :yes:

Then watching the voltage of each cell to make sure everything was going right, I noticed my home-made 16 Ga wire lead off the charger was getting pretty warm. LOL

I believe the small Ga. charger lead was why it was "only" charging at 36 amps.

The packs didn't seem to mind this at all! I can't believe it really.

From fully Dead, to fully charged took less than 10 minutes. Again, I didn't detect any heat being added from the high charge rate. Then out for another run. Same Power, Same Punch.

36 amps is 8C. They can handle it!

IF any of you guys try this, remember, the Automotive charger ONLY works if you charge 4S in series.

I checked the balance of each pack. The cells are still within .003 volts of each other. :yipi: They haven't been balanced since New, only checked.

Not bad for "reject" cells huh? :rofl:

Not bad at all for rejects. Have anyone tried it with the grade A cells from you know who?

I'd offer to try, but I would need to take out a second mortgage on the house to buy the packs!

Make sure someone shoves all this info under Jason's nose on whatever forum hes lurking on, love to see what his responce will be, if any. When he refuses to issue his own graphes and charge/discharge data, it'll be plain as day that MA are all mouth & no trousers... :no:

MA could've done something like this: http://www.rcgroups.com/forums/showthread.php?t=1078049, but I think the MA boys don't know how to hack the graphs to make them look good :lol: and that's the reason they don't post anything. Here's a thread with good results so far: http://www.rcgroups.com/forums/showt...1143540&page=2.

sikeston34m post your info there and call out the MA guys to see what they can say about the reject cells :lol:.

Those guys are watching this thread. That's why they accused you and BN of playing games between there and "another" forum.

It's because they are watching this thread and the "60C really?" thread.

They are alot of "Talk". The proof is in the pudding.

That's why we should put these packs up against their "Green" packs on legit discharge equipment. Or at least an Eagletree running the same setup.

I really enjoyed seeing the discharge graphs in the link you posted Lutach.

I do believe these are holding voltage above 3.0 - 3.1 volts per cell right up to the very end. The discharge curve is VERY flat and at the end they drop suddenly.

I'm tempted to setup my E Revo with these also, then buy another Automotive charger.

Picture two Monster Trucks geared for 40mph, being charged in less than 10 minutes, only to do another 30 minute run.

It's a play all day kinda setup. :yes:

Interesting, I have a really nice automotive charger at the shop, all digital. It has a 6v setting too... Maybe I should try the 2s pack on that? HeHe, it can do 60 amps... What does that work out to, 13+c....

Maybe stick to the 20 amp setting, that should still do the job in 15 mins. I am sure some of the plane guys will try a 3s pack with the "zip charging" method. That is basically a 12v power supply (A big one that can be set) and a certain length of certain gauge wire to limit the current. One guy was charging the 2300 cells in 3 or 4 mins....And had hundreds of cycles as well.

The 6 volt setting should work fine for 2S.

Recommended charge cutoff is 3.6 volts per cell.

I opened up my "Black and Decker :rofl:" automotive charger and soldered a "little" 16 Ga. lead directly to the outputs on the board.

The cells topped off right at 3.55 volts per cell. Slight Calibration error, or added resistence in the lead? Not sure, but it works perfectly.

My advice is, make sure your charger terminates charge on the 6 volt setting at 7.2 volts or less and you're good to go. :yes:

Wait a second! I'm sure if you "surf" the net, you could find a "GREEN" Lifepo4 charger for $567,789,234 Gazillion dollars!

It's the BEST too! Much better than all those other "reject" chargers!

:rofl:

I am glad to see you guys talking about these, I have been wanting a set of LiFe for my E-Maxx that does not have lipo cut off. I had wondered about these, they seemed almost to good to be true, considering the amount a certain website that advertises a lot wants for theirs......

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

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.

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 :smile:

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.

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?

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..

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?

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...

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...

I've seen the hvmaxx esc handle 5s2p, but that is slightly different to an evx2..

Parallel setup has nothing to do with voltage (normal cell count)- its just an easy method to double the runtime & reduce the voltage droop under load ( a stock brushed setup isnt gonna pull alot of current regardless).

Your esc is setup to use a pair of packs in series (2x 2s for example), so you will have to either rewire your esc to take a pair of 5s packs in parallel, or just do like Linc said and use a normal 2s Life pack on each input.

You seem to be over-thinking things- its nowhere near as complicated as you imagine- read my tutotials page, should help abit:

http://robotwars.00server.com/tutorials.html

In all fairness, MA may be correct in saying they are "reject" cells. However, one should not assume that rejected material is bad material. Rejected material maybe 99% quality of accepted material, and no differences may be noticed in anything but specific bench tests.

Any manu process will have a failure/rejection rate. What is done with this scrap material is interesting. There is no reason why a manu can't classify grades of reject material and sell them as such wholesale. Its a common practice in many industries.

Outlet stores began as sellers as "reject" or surplus material. Lots of people still find good deals and qualty goods at outlet stores.
EG: I really like Le Creuset cookware, but its very expensive MSRP. I buy all my cookware as seconds at their outlet stores. For much of the products, you can not tell the diff from the firsts and seconds, and the few you can are usually due to minor cosmetic errors. However, they did fail QC as a first run material, and are not sold as such. I am very happy with all my seconds, and more happy with the 70% less I paid for it. I can promise you it makes no fraking difference in how the food comes out.

Can the EVX2 handle 14cells NIMH? Even 5S Life is 18.25V, which is less than 13cells NIMH fully charged. Hard to believe they would make the specs that tight that it wouldn't work, then again, if you blow it up, don't blame me.

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?

That should work fine- 2s on the BEC side, 3s on the other.

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.

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. :yes:

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

Thanks for the update sike...I am thinking of getting some of these for my daughter's truck

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.

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.

This would be best to make a saddle pack, but you have to stack a few of them to get the capacity up enough. The factory can do other sizes, but need a large enough order though. The size of that one is: 10mm X 45mm x 43mm.

These are cells you have access to? How much are they? 2x 5s1p or 6s1p 2250 would be perfect for my HV Savvy. What is the burst? I see A spikes usually in the 65A range, and upto 90A. That's only 40C max.

LMK

I have access to basically all the manufacturers of cells in Asia. I haven't asked for price for any of them since I really don't have any interest of having liabilities nightmares incase something goes wrong :lol:. I'm in the process of having 2 LiFePo4 cylindrical cells made and it should take around 30 days. One is a 2/3A size for minis and it should have a capacity of 300-500mAh and a Sub-C size one with a capacity of 1200-1400mAh. I can get pricing and MOQ if you want. Also, they'll be fresh cells so it should take around 30 days to get them made.

I think you would love the following then. See pics :surprised:. Should I get them all here and mess with MA a little? I really don't care about making a profit on them and I would just have people sign :rules: some paperwork that would clear my name from any wrong doing if they get hurt in any way, shape or form. What do you think?

Edit: The size for the 2700mAh is: 7.5mm X 43mm X 125mm.