Lipo VS A123 (Full Version)

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GiantScale -> Lipo VS A123 (11/30/2007 4:20:11 PM)

Correct me if Im wrong..

A123's are safer. Wont catch fire.
They charge twice as fast as lipo's
A123's weight more and are larger than equivalent mah lipo's

Are these A123's going to replace lipo batteries eventually? This is getting old.. Nimh, then lipo's, now A123's.. and expensive.



SS Pede -> RE: Lipo VS A123 (11/30/2007 8:56:43 PM)

They seem like more of an alternative to LiPo than a replacement for LiPo. Ounce for ounce, LiPo packs tend to offer more higher capacity and higher voltage (better performance). It's all a matter of weighing the pros and cons and seeing which is best for you (personally I have not yet decided on one or the other [&:] ).



dick Hanson -> RE: Lipo VS A123 (11/30/2007 11:48:21 PM)

I use both all the time - frankly if the choice is even a good possibility -I use the A123

I have the latest LiPos from TP and both sizes A123 - 1100 and 2300 ma cells
The small models -of course LiPos up to 16 ounces



SinCityJets -> RE: Lipo VS A123 (12/1/2007 5:36:24 PM)


quote:

ORIGINAL: SS Pede

They seem like more of an alternative to LiPo than a replacement for LiPo. Ounce for ounce, LiPo packs tend to offer more higher capacity and higher voltage (better performance). It's all a matter of weighing the pros and cons and seeing which is best for you (personally I have not yet decided on one or the other [&:] ).


I am going to have to disagree about the voltage (performance) statement. Voltage is just an indicator of how many cells are in series. As far as performance, these batteries offer the a higher C rating than any lipo currently on the market. Not to mention you can charge them 5 times faster, their MUCH safer, and they last (lifespan) 5-10 times longer.

Bottom line, if the vehicle is big enough for an A123, use it.



GiantScale -> RE: Lipo VS A123 (12/1/2007 10:21:34 PM)

Thanks all. Lots of advantages for the sport modeler.

I think these A123's may have a bright future. But as of right now the record holders are sticking with the lipo's. The IR is to high unless you zapp and preheat them. From what I understand.



SinCityJets -> RE: Lipo VS A123 (12/2/2007 1:01:45 AM)


quote:

ORIGINAL: GiantScale

The IR is to high unless you zapp and preheat them. From what I understand.


GS, what are you referring to when you say the "IR is too high"?



GiantScale -> RE: Lipo VS A123 (12/2/2007 1:37:25 AM)


IR= internal resistance

Im not as educated about batteries as a few folks (record holders) I recognize in these threads. Im a follower.
http://www.rumrunnerracing.com/feforums/showthread.php?t=20597&highlight=A123

http://www.rumrunnerracing.com/feforums/showthread.php?t=22537&highlight=A123

This is what one fellow had to do to get them to perform..

This cells can pushed and then the internal resistance goes down by 25% .If you want to use this cells under high amp load you have to heat them up.The procedure is ,that you have to charge them with 15 Amps till full.This is to heat ,so you have now to discarge them under 50 Amps load to reach a temperature of about 50°C .Now you can recharge the left cappacity from the heat cycle with 15 amps and Now the cell is raedy for oval or SAW contest.
Then the cell is like a IB 4200 cell.




SinCityJets -> RE: Lipo VS A123 (12/2/2007 3:05:33 AM)

If you plan on going for records, then that may (or may not) be good advice.

but, if you're looking for the safest, highest discharge capable, highest charge capable, most cycles of any other battery on the market, then I would have to go with the A123.



Rickochet -> RE: Lipo VS A123 (12/2/2007 3:13:19 AM)


quote:

ORIGINAL: GiantScale

Thanks all. Lots of advantages for the sport modeler.

I think these A123's may have a bright future. But as of right now the record holders are sticking with the lipo's. The IR is to high unless you zapp and preheat them. From what I understand.


Good point, and I think Sport Flyer relates to most of us here.



dick Hanson -> RE: Lipo VS A123 (12/2/2007 6:06:46 PM)

LiPos beat em every time -- weightwise ---after that - it's all down hill
Talk to guys who activelyuse both type cells -
even my 4 cell 1100 ma B&D pack does a bang up job of aggressive flying a 22ounce all up , 430 sq in model . sur shorter flights but -fine with me -I don't fly enduros.
My LiPos? I will keep em (those at 2100 ma 3 cell or smaller ) but after that --- NFW!
The " competition" guys who DGAS about costs ? keep yer LiPos and have fun-it's a hobby--
Frankly , I can outfit a really good flying aerobatic setup for faar less and still have lotsa fun-with no concern about fires (real issue flying in dry fields ) and I recharge and am back up in a half an hour. big n little packs
Having done competitive setups for toooo many years -I may sound like I don't care about performance - guess again kemosabee. These suckers really are a step forward.



SS Pede -> RE: Lipo VS A123 (12/2/2007 8:15:52 PM)

quote:

I am going to have to disagree about the voltage (performance) statement. Voltage is just an indicator of how many cells are in series. As far as performance, these batteries offer the a higher C rating than any lipo currently on the market.

True enough, they do have a higher C rating than LiPo. But at high discharge rates doesn't the voltage of A123's drop farther than good LiPo's? Maybe this is where I was getting my original impression. Yes, the C rating is great, but I still get the sense that for "ultimate" performance (maybe not for so many people in this forum) LiPo still has the edge. True or no?



snellemin -> RE: Lipo VS A123 (12/2/2007 8:33:02 PM)

If the voltage drop is such a concern, you can always put 2 in parallel and have less voltage drop. In my case, I'm only concerned with massive voltage drop during dragracing.



SinCityJets -> RE: Lipo VS A123 (12/2/2007 11:37:30 PM)

SS,

You have it just the opposite. A 3 cell lipo drops from 12.6 to 10.5, almost IMMEDIATELY when running them hard. They also have a constant discharge rate, so the voltage is constantly dropping from 10.5 until they reach their cut-off point (9 volts or whatever you have the cut-off set at)

A123's on the other hand, discharge almost flat. A 3 cell A123 (10.8 to start) will only drop to 10.2 for most of the duration of the discharge, until reaching cut-off. The only "negative" is that voltage is NOT a good indicator of how much energy is left in these cells. Because their discharge curve is so flat, you have to become "familiar" with these cells by flying them, and then charging them to gauge how many Mah you used. After doing this a few times, you will learn how many flights/minutes you can get out of a pack.

Of course you could also use an in-flight data recorder that records amps, volts, power used during a flight. I guess you could use them on the ground or water too.



dick Hanson -> RE: Lipo VS A123 (12/3/2007 12:33:09 AM)

I got rid of my Lipo 2200 packs when I compared them under load with my A123 packs - and as noted in above response the A123 beat the LiPos by a goodly amount in voltage holding stability -
I even doubled the LiPo packs and the single A123 still beat it. ( 3 cell TP (two pack)vs 4 cell A123)
I know the first response is always to look at stats then decide which is best -
On paper the LiPos look best
In actual use - I find the A123 beat the claims and the LiPos don't live up to the claims - I don't sell either - so no axe to grind . But --- if you prefer LiPos have at it - I was using a 32 EFite motor a 75 amp ALIGN controller - and a 13x6.4 APC prop and reading voltages with a Astro Flite WHATTMETER
I was comparing total watts pulled and watts during various stages of pack depletion. Of course I started with higher voltage but the differences in voltage drop - per packs - was what I was interested in



SinCityJets -> RE: Lipo VS A123 (12/3/2007 12:51:02 AM)

And I sell both, but I too have to go with A123's!! [;)]



SS Pede -> RE: Lipo VS A123 (12/3/2007 1:34:43 AM)

I would actually be driving, not flying. [:)] So luckily I don't have to worry about my truck falling out of the sky when the batteries run out!

Going back to what snellemin said about A123 cells in parallel, I am wondering about the performance of the new A123 cells versus the larger, original cells. Specifically, say I am going for a pack that is close to the size of a normal stick pack. That would be the 2s1p pack with the larger cells, for 2300 mAh. My other choice would be the 2s2p 2200 mAh pack of the new cells. I hear that the bigger cells perform a bit better than the smaller ones, perhaps as expected. But I'm wondering...what would the performance difference be between 2s1p of the old cells and 2s2p of the new ones? The newer pack has smaller cells, but they are arranged in parallel. Would this help performance much compared to the big A123 cells?



dick Hanson -> RE: Lipo VS A123 (12/3/2007 1:52:40 AM)

save yer muney - one 2300ma cell is slightly better than two of the 1100 ma cells in parallel
and slightly lighter
unless you have some special space consideration .
It is a close call but I fly both cells and measure refills of cells after runing till they start to fade - done it a number of times and for all PRACTICAL purposes the 1100 ma cell is 'bout 1/2 of the weight ,diameter and mah delivery.
If you are a fuss budget over fine points you will see this is not exact - just an overview.



hendrix -> RE: Lipo VS A123 (12/31/2007 10:44:35 AM)

Hi.
Please forgive me for intruding but i have plenty of A123 cells and plenty of lipos.
I work in a lab with the best equipment available and after some measurements and real life experience i will like
to add my opinion.
The lipo packs are better when weight savings is the main concern but all the other aspects are against the lipo chemistry.
True that the IR is higher from the high C lipo cells but the A123 cells can give almost 100% of their rated capacity
where the lipos can only go up to 70 ~ 80% before they permanently start to loose capacity,
have a flat discharge voltage curve which means constant power level throughout the whole flight,
are safer and more robust then lipos and finally their life measured in charge discharge cycles is far longer than any lipo.
I have actually saved money by switching to A123 by not having to replace my lipos so often. I don't know about others but the mean cycle life of my lipos
never exceeded 30 charge - discharge cycles before loosing more than 20% of their rated capacity and i can assure you i have never pushed any lipo beyond the rated C * 0,7 mark (i only use a 20C lipo at 14C max, a 15C at 10C and so on)
My planes stay much longer in the air with a A123 pack than with the lipo equivalent pack although the lipo pack is lighter.
Also if you want cheap A123 cells the the Dewalt 36V pack is perfect[:D]
As i final note i would like to add that i have been following the lipo chemistry since it's birth and i have payed big bucks for the early lipo packs,
i even got a 3S 6Ah pack (very big and heavy) back in 2001 directly from a factory but now i wish that A123 comes out with a bigger capacity cell than the
current ~2300 mAh cell.
Chris



mightynova63 -> RE: Lipo VS A123 (1/8/2008 12:23:12 AM)

Can a DuraTrax ICE charger be used on the A123 packs



mscj -> RE: Lipo VS A123 (1/8/2008 2:16:52 AM)


quote:

ORIGINAL: mightynova63

Can a DuraTrax ICE charger be used on the A123 packs



Yes it can--as long as devices to limit the charge voltage are used....like this
or, if you're a DIY type, this.
I received two of the units in the first link today, quick test shows charge cut off around 3.8 volts per cell.....



mightynova63 -> RE: Lipo VS A123 (1/8/2008 8:52:57 PM)

so how do you balance with that



everydayflyer -> RE: Lipo VS A123 (1/8/2008 9:44:32 PM)

If you want to charge and balance with a Ni charger get a Hyperion LBA10 balancer.



mightynova63 -> RE: Lipo VS A123 (1/8/2008 10:41:28 PM)

If i use the hyperion balancer do i still need the A123 Dapoter or do i use both



everydayflyer -> RE: Lipo VS A123 (1/8/2008 11:20:21 PM)

If the LBA10 works in the A123 mode the same as the LBA6 did in the LiPoly mode then you only need the LBA10.

Reason LBA6 has an over-voltage safety disconnect which stoped the charger if any cell reached approx. 4.3 volts (LiPolys). I know the 10 has a A123 mode but do not know at what voltage it cuts off.


IMO the ICE can be used to charge A123 packs on the LiPoly setting but I get tired of arguring the point.

A123 cells are not seriously injured if charged to 4.2 volts per cell.
Ther I said it again.

FYI Some are using chargers with a Pb 12V mode to charge 4S A123 packs.
4X3.6=14.4 volts which is close to same as 12Pb is charged to.




charlles



dick Hanson -> RE: Lipo VS A123 (1/8/2008 11:28:33 PM)

For those who don't know -- the charging circuit in most autos provides 14+ v (14.2/14.4V) for 12 volt lead acid /deep cycle etc., setups.



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