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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Have any tried A123 packs from ElectroDynamics?<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><a href="https://electrodynam.com/rc/">https://electrodynam.com/rc/</a><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Dave Burton<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
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<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
nsrca-discussion-bounces@lists.nsrca.org
[mailto:nsrca-discussion-bounces@lists.nsrca.org] <b>On Behalf Of </b>Keith
Hoard<br>
<b>Sent:</b> Saturday, September 06, 2008 10:39 AM<br>
<b>To:</b> General pattern discussion<br>
<b>Subject:</b> Re: [NSRCA-discussion] A123 Batteries?<o:p></o:p></span></p>
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<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal style='margin-bottom:12.0pt'>John,<br>
<br>
I have done ALOT of testing of the A123 batteries, both the 2300 and 1100 Mah
versions. The first thing you need to make sure is that they have the
"A123" label on the side. The "LiFe" batteries
(Iron-Corps) batteries are NOT the same batteries and have a higher internal
resistance.<br>
<br>
When I tested the A123's, I charge them up and discharge them on my West
Mountain CBA. I have discharged the 2300's at 0.5 Amps, then15 Amps, then
another dishcarge at 0.5 Amps and they showed no loss of capacity between the
two .5 Amp discharges - no rest in between. Max temp during the 15A
discharge was 109F. Try that with a 2300 Mah LiPo. I can e-mail you
copies of the CBA discharges if you want. . . I also similarly abused the 1100
Mah versions with the same results (except I used 4 Amps continuous, not sure
how long the 20 gauge wire or Futaba connector would last at 15Amps)<br>
<br>
At what point did you measure the imbalance? If it was at the end of the
discharge, then yes, they will go out of balance there. But when you
start charging them, they will quickly come back into balance. The great
thing about these batteries is that you can run them flat over and over and all
you have to do is hook up the juice to them and they will charge right
up. If you're still concerned I can record a few charge cycles on my 10S
charger and it will show you how the cells go out of balance at the end of
their discharge and then back into balance soon into the charge cycle.<br>
<br>
Yes, the A123's drop right off a cliff if you run them all the way out to their
capacity. This requires different handling than previous cell
chemistries. <br>
<br>
First of all, you cannot "fuel gauge" these batteries the way we did
with the other chemistries. The reason for this is also one of the great
strengths of these batteries. The A123 cells hold their voltage under
heavy amperage, so getting a good number would require heavy gauge wire and a
Deans connector. So obviously, the key with these batteries is to never
get close to the cliff.<br>
<br>
One solution is what Fromeco did, sell you another switch that measures how
many Mah you have taken out of the battery since your last charge.
However, I use a much simpler and cheaper method. I plug in my FMA 4S
charger at soon as I park my plane and it is finished topping off the battery
before I'm done filling the fuel tank. I then mentally note how much
charge was put back in - right at 120 Mah each flight, so I <i>could</i> go 4-5
flights between charges, but why? It is just as easy to top off the
battery after each flight.<br>
<br>
<o:p></o:p></p>
<div>
<p class=MsoNormal>On Sat, Sep 6, 2008 at 6:35 AM, John Konneker <<a
href="mailto:jlkonn@hotmail.com">jlkonn@hotmail.com</a>> wrote:<o:p></o:p></p>
<div>
<p class=MsoNormal style='margin-bottom:12.0pt'>Hi Keith,<br>
I bought one of the WalMart VPX packs to experiment with.<br>
I followed the instructions on Bob Pastorello's website for it's
disassembly and adaptation.<br>
It handled the high, 4C, charge and discharge rates as advertised but there
were two things that made me hesitate to <br>
use the pack in a plane...might have been just my pack or how I originally
handled it.<br>
1- When discharging the pack in cycle mode on my BC-6 the two cells would go
way out of balance. The BC-6 and my CellPro 4s would <br>
always bring them back in to balance when balance charging, I had wired a
balance plug in to it, but this concerned me. Like I said it could have
been my particular pack.<br>
2- When they say the capacity is 1,000 or 1,100 mah, whatever, they aren't
kidding. As the BC-6 would near this value when cycling the<br>
pack voltage would drop so fast you could hardly read the numbers. It was
like it hit the wall and fell off a cliff. This also concerned me.<br>
<br>
I would be interested if other folks have had similar experience with the VPX
packs. Like I said it could have been something I did or the <br>
individual pack I got. I know the A123's offer great potential. In
fact there was a Sportsman pilot here in D5 at the St Louis contest that<br>
flew an A123 powered Fliton plane. I plane to write it up in my next
column but you can see and read about him now on Chris Moon's new<br>
electric webpage.<br>
JLK<br>
<br>
<o:p></o:p></p>
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<p class=MsoNormal><br>
Date: Fri, 5 Sep 2008 21:22:15 -0500<br>
From: <a href="mailto:khoard@gmail.com" target="_blank">khoard@gmail.com</a><br>
To: <a href="mailto:nsrca-discussion@lists.nsrca.org" target="_blank">nsrca-discussion@lists.nsrca.org</a><br>
Subject: Re: [NSRCA-discussion] A123 Batteries?<o:p></o:p></p>
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<div>
<p class=MsoNormal style='margin-bottom:12.0pt'><br>
<br>
<o:p></o:p></p>
<div>
<p class=MsoNormal style='margin-bottom:12.0pt'>I love 'em. I buy the
2-cell 1100 Mah VPX packs from Wal-Mart and strip out the cells. <br>
<br>
Then I wire them up with 20-gauge Futaba connector, using the white wire for
the Node-1 tap. I charge them after every flight with the FMA CellPro
charger.<br>
<br>
On my 50cc airplane, I'm using two packs unregulated in parallel plugged
directly into the 6014 receiver, and another pack unregulated on the
igntion. <br>
<br>
On my pattern plane, I'm using one pack unregulated - no problems whatsoever.<o:p></o:p></p>
<div>
<p class=MsoNormal>On Fri, Sep 5, 2008 at 8:13 PM, Joe Dunnaway <<a
href="mailto:dunnaway@hbcomm.net" target="_blank">dunnaway@hbcomm.net</a>>
wrote:<o:p></o:p></p>
<p class=MsoNormal> Anyone using A123 cells for your receiver batteries?
Any problems, advice or hints? What chargers? <br>
<br>
Thanks<br>
<span style='color:#888888'>Joe Dunnaway<br>
_______________________________________________<br>
NSRCA-discussion mailing list<br>
<a href="mailto:NSRCA-discussion@lists.nsrca.org" target="_blank">NSRCA-discussion@lists.nsrca.org</a><br>
<a href="http://lists.nsrca.org/mailman/listinfo/nsrca-discussion"
target="_blank">http://lists.nsrca.org/mailman/listinfo/nsrca-discussion</a></span><o:p></o:p></p>
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<p class=MsoNormal style='margin-bottom:12.0pt'><br>
<br clear=all>
<br>
-- <br>
<br>
Keith Hoard<br>
Collierville, TN<br>
<a href="mailto:khoard@gmail.com" target="_blank">khoard@gmail.com</a><br>
<br>
<o:p></o:p></p>
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<p class=MsoNormal><br>
_______________________________________________<br>
NSRCA-discussion mailing list<br>
<a href="mailto:NSRCA-discussion@lists.nsrca.org">NSRCA-discussion@lists.nsrca.org</a><br>
<a href="http://lists.nsrca.org/mailman/listinfo/nsrca-discussion"
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<p class=MsoNormal style='margin-bottom:12.0pt'><br>
<br clear=all>
<br>
-- <br>
<br>
Keith Hoard<br>
Collierville, TN<br>
<a href="mailto:khoard@gmail.com">khoard@gmail.com</a><br>
<br>
<o:p></o:p></p>
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