everydayflyer

Eagle tree just posted Beta 4.44 of their application software which had some bug fixs so I did a test run this morning.
Traxxas Rustler CC Mamba Max 5700 ,3S A123. This was discharge # 171 and I have hammered this pack hard. Watts and Amps. down a bit thismorning as it was 30F and the groud was wet ans slick. Major wheel spins and spin outs.
Logging trigger set at 3A so no recording below that level. (only runtime above 3A recordered). Total clock time was 11-1/2 minutes as I did flip a few tijes and took a couple of 30 second timeouts to check logging triger.

A few days ago I did a full charge in 4:18 and two days ago I did a discharge down to 4volts.

Charles

everydayflyer

Here is my 4:18 charge Graph.
Ignor the initial 108A spike(false start).
Note that most of the charge was in the 36 to 30A range.

Charles

madmoony

Wow,that's impressive! Start current over 108 Amps.That's really a "quick charge".How are the cells performing after that torture?Any sags in capacity or Ri ?

Burkhard

everydayflyer

I should have noted to ignore that initial spike. The charge started at 78A and quickly droped to apprxox. 36A and then a more natural taper to 30A.

Post righ above charge graph was run approx. 5 cycles after that fast charge.
I do not bother to check IR but I have not seen any difference in performance or capacity.

Charles

everydayflyer

Here is a link to run ( discharge) #171.

http://www.rcgroups.com/forums/showp...&postcount=574

SS Pede

Even ignoring the spike at the beginning, 30 amps is a HUGE charge current! I'm very impressed that the a123's handle this current without any apparent problems. Most other batts would be toast.

A123 Racing

Hey Charles,

I am glad to see that you are happy with your batteries. I am even happier to see you providing all your data to other enthusiasts. I am sure they are grateful. Our batteries are capable of Very high charge currents. There are two things to note when charging with this kind of current. 1.) You should monitor your cell voltages more carefully as charging with higher current can have a greater effect on cell deviation. 2.) This kind of charging will have an impact on your pack’s cycle life. This reason is also why we do not typically charge them with these high currents. We chose 10 amps because 15 minutes is a great charge time, and we want peoples packs to last as long as possible.

Good luck, keep the data coming,

Brian

[link=http://www.a123racing.com][/link]

everydayflyer

CBA software has a few strange feactures so first discharge is listed as 185 not 1.
To much trouble to edit so just ignore it.

First discharge was 2190 mAh and the last one was 2100 mAh.

One day this battery will wear out or fail, it has to but for now it continues to impress the you know what out of me.

Added a second Graph (non expanded).



Charles

Pinolelst

I want to see graphs 10 second discharge rates at 100 amps. That's what my hotliner sees climb after climb .... and I want to know if these cells will fit in the same space that a 4s 5000 lipo fits easily in and provide the same performance and longevity....oh..and weigh the same or less at same parameters....and not get beyond slightly warm while doing it...
Thanks for your time

pinolelst

rivanna

My Feedback: (1)

First of all thanks for your info---all contributors!!!I have been using Jeti 77Opto Esc and 2 -11.1 vlt TP4400 packs with an AXI 4120 motor to pqwer a .60 sized Extra 300. Based on what I have read,I started making 4cell A123 packs to act as replacements for th TP's. Will this work and will I have a problem with cutoffs on the ESC.T.I.A.

adamd11pl

Hey Charles,
Any update? Or have you just finish testing on #185?

Regards
Adam

Red Scholefield

My Feedback: (9)

A123's are probably not for you. Sorry. They are larger and will weigh more and have less capacity. They are for the sport flyer that wants to wear out his 40 size sport plane before the pack wears out.

Kraeuterbutter

@Charles: already past 200 cycles ?

i have already 40cycles in my heli with them..
empty them within 4,5-5min (most times not totally empty) and recharge them with 8A... (most times i get 1800-2000mah back in)

sofar no problems...
like the cells VERY MUCH

Bass1

Do we have an oppinion change on the a123 cells yet? [sm=idea.gif]

baby2kent

Just a quick question, I am planning on using 2 of the A123 4600mah 6.6 volt packs with a 1/8th buggy Bl conversion, what kind of runtimes will i be able to get and how does the power compare to a NiMh 7.2v pack(i know the voltage is lower on the A123 pack but i think the amps will more than make up for that?)

andy38

can someone tell me if the astroflight 110D charger auto detects the number of cells or is it set by the user. I want to use it with the
LiipoDapter+ to charge M1 cells.

DLS II

The AFI 110 Deluxe auto detects the # of nicad/nimh cells in your pack. In combination with a lipodapter it works fine charging up A123 packs. I have 2 4s A123 packs, they both charged up fine with that combo-@ 8 amps. Don

jetjockey69

My Feedback: (31)

I'm thinking of going to A123 cells to power all the electronics/servos in an upcoming turbine jet project. Never used A123 batteries before, but everything I read tells me that is the way to go. I need some advice.

What is the best charger/balancer combination to use for these batteries? Who is the best vendor for some ready-made packs? Ideally, I'd like to have packs in the following capacities:
2-cell, 4000mah
3-cell, 4000mah

I'm also considering getting out of glow and gas powered prop planes and going to all electric. The only reason for this is because I no longer have much time to travel the distance I need to go to get to the club field but can fly at a farm and other fields much closer to home if I don't have to deal with the noise issues associated with gas or glow powered models. A123 batteries seem to provide the level of safety and versatility that makes it worthwhile for me to change over.

Kraeuterbutter

every day flyer:
whats with your life-test ?
how many cycles ?
how do the cells performe ?

thx,
Reini

Smash McCrash

EveryDayFlyer: I see that you are using the 1010C and 210B for charging the A123's. How are you liking it and is it doing a good job? I just updated mine to 2.1C and have my first DC9360 on its way to tear into and make some packs. Just looking for more info that no-one at the other board seems to be able to answer.

Thanks!

Mike

everydayflyer

Well these cells just continue to amaze me. A 3S pack in my MUS (Mini Ultra Stick) now has 436 flights on it and is has been charged 411 of those times in under 8 minutes. Average charge time is 6 1/2 minutes and average capacity used per flight is 1900 mAh. that gives an average charge rtae of 17.5 amps. Charge starts at approx. 25 amps. and tapers to approx. 8 amps when charger is terminated at 11.55 volts (3.85 per cell).This one is down to approx. 2050 mAh capacity.

My 4S and 5S packs get charged on m y TP1010C / 210V combo at 10amps. and I have obtained a Cell Pro10 recentl which also charge them at 10 amps. Greates number of flights on a 4 cell to date is around 250 and another is close to 200. All of the packs are doing well with very little capacity loose.



Charles

Red Scholefield

My Feedback: (9)

Charles has my A123 performance beat by a mile. But just to add to the data bank I have been flying 4S2300 A123 packs since June of 06. Here in the sunshine state we fly pretty much year round. I have logged over 250 charge cycles on my A123s with them still going over 2000 mAh on a bench discharge. All charges were on a CellPro 4S @ 3 amps until just recently when I put a CellPro 10S into play. Since I seldom charge at the field I charge at 1 amp on the bench now with the 10S. Have a 4S1100 mAH VPX pack with only a few cycles to date but performance is fine in my Tantrum (Mountain Models).

Red Scholefield

My Feedback: (9)

Hard to believe! I left the switch on in my ULTIMATE 10 DASH 300 (4S2300 A123 pack). I was probably on for several weeks at least. Voltage read zero. CellPro 4S would not charge - voltage too low indication. So I put it on my Triton II charging in Ni-Cd mode at 200 mA. The voltage started up immediately, after about 20 minutes it was up to 10 volts or so, then put it on the CellPro 4S @ 3.0 amps. CellPro went into restore mode and continued the charge until it had put in 2408 mAh, all cells balanced out nicely.

But did I still have a usable battery? Ran it on my ULTIMATE WOT for 6 minutes (AXI 2808-24 w/10X6 Graupner prop). It did not seem to have lost any punch. Back on CellPro - fuel = 15%. Now it is charging normally.

I would not have believed it!

A day later - flew them this morning, they performed like nothing had happened. It still blows my mind.

SS Pede

Wow. These cells are absolute tanks. As much as LiPo may have them beat in terms of energy density and convenient size (for cars), these seem like really easy cells to live with. It would be so nice to not have to worry about charge/discharge rates, low voltage cutoffs, storage methods, cycle life, etc. etc. etc.

Does anyone have any new stories of these cells in cars, particularly in 2s1p configuration?

Red Scholefield

My Feedback: (9)

Better yet, does any one have any failure reports on them? They have been in use for over two years now, you would think that someone would be creative enough to screw them up.