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All Forums >> Radios, Batteries, Clubhouse and more >> Batteries & Chargers >> A123Racing Support >> how long will A123 last in my application ?
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how long will A123 last in my application ? - 2/20/2007 2:50:08 PM   
Kraeuterbutter


 

Posts: 26
Joined: 10/10/2003
From: Viennaaustria, AUSTRIA
Status: offline 		i see this values in my Heli:






the peaks of 90A+ are shorter max. 1sec long (or shorter)
and as you can see seldom during one discharge

its more like 60A peaks in general
and 20A-25A average current at discharge

i also don´t run the batts completley empty (because the heli comes down like a stone on that !)
so: around 1800mAh discharged

charing: 4A at home, 8A at the field

what kind of lifetime can i expect ?!?

more than 500 ?






       Post #: 1

RE: how long will A123 last in my application ? - 2/20/2007 5:11:15 PM   
A123 Racing


 

Posts: 102
Joined: 8/25/2006
From: Hopkinton, MA, USA
Status: offline 		Hello,

Thank you for using our batteries I hope you are enjoying the performance they offer in your heli. Based on our definition of end of discharge which is 15% capacity loss I would not expect to see 500 cycles on this pack, we would estimate 300-400 cycles, though our data in the RC heli application is limited. If you base your definition of end of discharge at 50% capacity loss then 500 cycles is possible.

Brian,


(in reply to Kraeuterbutter)
       Post #: 2

RE: how long will A123 last in my application ? - 2/21/2007 9:39:37 PM   
Kraeuterbutter


 

Posts: 26
Joined: 10/10/2003
From: Viennaaustria, AUSTRIA
Status: offline 		hey.. yes i was surprised..
work better than i expected

compared to NiMh they are great !

if you want best power together with long runtimes there is of course still no way around Lipos

unfortunatly i have killed my eagle-tree datalogger that same day..
so no more testing, only data of 2 days testing..

some thing i noticed:

batts charged 1st time ... flown
charged the warm batteries...
made 2nd flight 30min after end of charging (batts slightly warmer than normal room temp)

the values are the ones i have posted here

after this flight charged again

and flown 12hours later at the next day
---> the values looged were not that good

as said: i had only this 3 tests, than smoked my eagle-tree

my feeling: the A123 like it to use them imediatly after charging
when lying around days the power is not that good anymore

was that a mistake ? falls measurments ? ...
thx

(in reply to A123 Racing)
       Post #: 3

RE: how long will A123 last in my application ? - 2/23/2007 9:25:38 PM   
A123 Racing


 

Posts: 102
Joined: 8/25/2006
From: Hopkinton, MA, USA
Status: offline 		Hello,

I think you may have had something go wrong on hte second charge and or the thrid flight. Our batteires have an extremely long shelf life, they can be stored for months. The only difference you would see is that directly off a charger the batteries should be 3.6V / cell. If they are left to sit by htey will return to ther nominal voltage of 3.3V / cell, but even this should not be a drastic change becuase during use direclty off hte charger they will fall to niminal voltage pretty quickly.

Brian

Power . Safety . Life


(in reply to Kraeuterbutter)
       Post #: 4

RE: how long will A123 last in my application ? - 2/24/2007 1:58:44 AM   
everydayflyer



Posts: 893
Joined: 8/21/2005
From: Buchanan, GA, USA
Status: offline 		The difference between warm from charging and room temp. can make a noticeable difference.

See first attachment here

http://www.rcuniverse.com/forum/fb.asp?m=5154318

Disch 20 and 35 room temp. others warm from charge, I now do all of my graphing right after a run and recharge so they are more consistent.


Notice that in graph here

http://www.rcuniverse.com/forum/fb.asp?m=5452102

I did not include discharge 20 and 35 as IMO they are not truely representative.

Charles

< Message edited by everydayflyer -- 2/24/2007 2:03:49 AM >

(in reply to A123 Racing)
       Post #: 5

RE: how long will A123 last in my application ? - 3/5/2007 11:40:34 PM   
Kraeuterbutter


 

Posts: 26
Joined: 10/10/2003
From: Viennaaustria, AUSTRIA
Status: offline 		A123 at 40A discharge, 20°C cell-temperature at start


A123 at 40A discharge, heated with an hair-heater to 40°C



more information:
http://www.rc-network.de/forum/showthread.php?t=63180

< Message edited by Kraeuterbutter -- 3/5/2007 11:41:24 PM >

(in reply to everydayflyer)
       Post #: 6

RE: how long will A123 last in my application ? - 3/5/2007 11:46:22 PM   
Kraeuterbutter


 

Posts: 26
Joined: 10/10/2003
From: Viennaaustria, AUSTRIA
Status: offline 		here similar:

both at 50A

20°C (red)
vs. 50°C (green)


temperature makes this cell A LOT better
more info: http://www.rc-network.de/forum/showpost.php?p=588818&postcount=6

< Message edited by Kraeuterbutter -- 3/5/2007 11:51:31 PM >

(in reply to Kraeuterbutter)
       Post #: 7

RE: how long will A123 last in my application ? - 4/17/2007 6:15:56 PM   
Kraeuterbutter


 

Posts: 26
Joined: 10/10/2003
From: Viennaaustria, AUSTRIA
Status: offline 		after 40 cycles cell work great..

meanwhile regeared the heli and using 5 instead of 4 cells..

to have a little impression, here a video of the heli with
5s1p A123 FePO4

http://www.kraeuterbutter.at/Videos2/Acrobat10_5s1p_FePo4_kleinere%20Version.avi

runtime with around 5min is a little short, but fast charging makes this negativ point become very small...

(in reply to Kraeuterbutter)
       Post #: 8

RE: how long will A123 last in my application ? - 4/18/2007 10:03:15 AM   
adamd11pl


 

Posts: 11
Joined: 2/5/2003
From: Warszawa, POLAND
Status: offline 		Hi Kraeuterbutter,
I fly with 12s2p and I'm very hapy with them. When I try 12s1p setup, I get very hot (55-60 C range) pack.
How hot is yours pack after flight?
I get 60A in peak on 12s2p and 50A on 12s1p. Thats almost your power range.

regards
Adam

PS
first graph - 12s2p
second graph - 12s1p

Attachments
Click to see fullsize image.
Click for fullsize 		Click to see fullsize image.
Click for fullsize


< Message edited by adamd11pl -- 4/18/2007 10:05:18 AM >

(in reply to Kraeuterbutter)
       Post #: 9

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