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<DIV><SPAN class=426170519-18112005><FONT face=Arial color=#0000ff size=2>Hi
Rich,</FONT></SPAN></DIV>
<DIV><SPAN class=426170519-18112005><FONT face=Arial color=#0000ff size=2>Yeah,
at 70A, you are going to use every little bit of 4.0 AHr. That's based on my
flying P07.</FONT></SPAN></DIV>
<DIV><SPAN class=426170519-18112005><FONT face=Arial color=#0000ff size=2>You
need a bare minimum of 5 AH so you aren't drawing the battery down too
far.</FONT></SPAN></DIV>
<DIV><SPAN class=426170519-18112005><FONT face=Arial color=#0000ff size=2>I
tested the FMA discharge protection module, for a while. It's a neat item,
though too heavy for much of us, and the connectors are not rated for our
currents.</FONT></SPAN></DIV>
<DIV><SPAN class=426170519-18112005><FONT face=Arial color=#0000ff size=2>It
shuts the throttle down if <U>any one</U> cell hits 3.0V.</FONT></SPAN></DIV>
<DIV><SPAN class=426170519-18112005><FONT face=Arial color=#0000ff size=2>With
some disassembnly and connecvtor replacement, it would be a great safety
item!</FONT></SPAN></DIV>
<DIV><SPAN class=426170519-18112005><FONT face=Arial color=#0000ff size=2>The
Skyvolt balancing charger is a dandy item, though. I will be using it hereafter.
I intentionally unbalanced a pack, and put it on: voila, charged and balanced
with no extra effort.</FONT></SPAN></DIV>
<DIV><SPAN class=426170519-18112005></SPAN><SPAN class=426170519-18112005><FONT
face=Arial color=#0000ff size=2>I have to make up an adapter to allow me to hook
a TP style balancer connector and Deans Ultra combo to its special output
connector.</FONT></SPAN></DIV>
<DIV><SPAN class=426170519-18112005><FONT face=Arial color=#0000ff size=2>I also
want to put together a rig so I can look at each cell voltage, conveniently, at
the end of a flight.</FONT></SPAN></DIV>
<DIV><SPAN class=426170519-18112005><FONT face=Arial color=#0000ff size=2>It
doesn't need to be done every flight, but often enough to see if a cell keeps
coming up weak. </FONT></SPAN></DIV>
<DIV><SPAN class=426170519-18112005><FONT face=Arial color=#0000ff size=2>That
would be replacement time.</FONT></SPAN></DIV>
<DIV><SPAN class=426170519-18112005><FONT face=Arial color=#0000ff size=2>more
to come,</FONT></SPAN></DIV>
<DIV><SPAN class=426170519-18112005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><FONT face="Times New Roman">Dean Pappas</FONT> <BR><FONT
face="Times New Roman">Sr. Design Engineer</FONT> <BR><FONT
face="Times New Roman">Kodeos Communications</FONT> <BR><FONT
face="Times New Roman">111 Corporate Blvd.</FONT> <BR><FONT
face="Times New Roman">South Plainfield, N.J. 07080</FONT> <BR><FONT
face="Times New Roman">(908) 222-7817 phone</FONT> <BR><FONT
face="Times New Roman">(908) 222-2392 fax</FONT> <BR><FONT
face="Times New Roman">d.pappas@kodeos.com</FONT> </DIV>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> discussion-request@nsrca.org
[mailto:discussion-request@nsrca.org]<B>On Behalf Of </B>Richard
Strickland<BR><B>Sent:</B> Friday, November 18, 2005 12:58 PM<BR><B>To:</B>
discussion@nsrca.org<BR><B>Subject:</B> Re: Discussion List
(Batteries)<BR><BR></FONT></DIV>
<DIV><FONT face=Arial size=2>Gray, Dean,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>While my experience wasn't the greatest--it
really wasn't all that bad once we had the bugs worked out. BTW, it was
a Hacker system like Jason's.</FONT></DIV>
<DIV><FONT face=Arial size=2>One of the issues was to determine how cool the
batteries needed to be before putting them back on charge; another was to make
sure you were not over or under charging. Another was to make sure they
were balanced. But for me it came down to weight and longevity.
Contrary to where your information is coming from, my understanding is
that modeling IS driving this battery segment along with the
military. I'm reasonably confident there will be significant
breakthroughs like that nano-tech unit(Toshiba or some other heavy-hitter like
that) posted earlier this year that will impact the market fairly
shortly. The 3200s were under-sized, but 4000s would be also. The
motors would peak out at 67-69 amps on application of full throttle and back
down to the 63-65 range. This system worked well, but we were too close
to the edge to lose any capacity and complete an FAI flight. Temps
started with a 40-50 degree rise when we started using them in the upper
70s and 80s and the same and a little more as ambient got warmer. They
got too hot. We also tend to fly out.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Realistically, if to get decent mileage out of
these things and have to stay close to 10C; then you've got to have at least
6000s+ and keep the weight down. I know zip about batteries, except how
to design conveyor systems for them, but they almost need to act like a
capacitor--very high charge, discharge rates, and unlimited cycles with
no damage. I can't imagine there aren't MANY folks working on that
concept.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Of course there are other alternatives--lighter
and/or smaller airframes, different motor, ESC, prop combinations--but if you
want unlimited vertical with 11 lbs--then your're going to draw 55-70
amps.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Richard</FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=gfowler@raytheon.com href="mailto:gfowler@raytheon.com">Gray E
Fowler</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, November 18, 2005 10:57
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Discussion List
(Batteries)</DIV>
<DIV><BR></DIV><BR><FONT face=sans-serif size=2>Richard</FONT> <BR><BR><FONT
face=sans-serif size=2>I am not a battery expert, but like everyone else on
the list that does not stop me from having an opinion about
batteries.</FONT> <BR><FONT face=sans-serif size=2>First, electric airplanes
do not exactly drive the battery market,......even if 50% of the FAI
finalists use them. No other applications </FONT><BR><FONT face=sans-serif
size=2>that I am aware of uses these batteries in the manner that we
attempt, which is that massive current draw. What electric planes do
</FONT><BR><FONT face=sans-serif size=2>to batteries is damaging, as
demonstrated by your 25 flights. </FONT> <BR><FONT face=sans-serif
size=2>I would not expect the battery market to develop a battery capable of
long life and extreme current draw since no one else uses </FONT><BR><FONT
face=sans-serif size=2>batteries in such a manner.</FONT> <BR><BR><FONT
face=sans-serif size=2>Invest in bottle of Windex, clean the oil.
</FONT><BR><BR><BR><BR><FONT size=2><TT>In fairness to the manufacturers, I
don't think they really understood that<BR>guys potentially would go out and
fly 50+ flights per week. When I finally<BR>got all my infrastructure
charging act together and made time to<BR>practice--which wasn't all that
much, I still was clicking along at a 35<BR>flight/week pace right up to our
first contest in mid June. As you may<BR>recall, I was using 20C
3200s on a shared cost beta program. At 11 lbs.,<BR>the airplanes were
gobbling up 63-68 amps at times and significantly heated<BR>the batteries
and shortened their lives. The manufacturer came out with<BR>some 15C
4000s--but there was still the problem of amp draw and heat.
The<BR>consensus at that point is the batteries aren't very happy at
much over 10C.<BR>The problem I had/have is anything over the smaller
batteries was going to<BR>blow the weight limit--plus, as more information
was coming out from some of<BR>the top guys that they were getting around
50-60 flights on the larger<BR>packs. Since I'm not a top dog, I would
pretty much have to foot the entire<BR>bill to switch to the larger units.
As it appeared to me--the batteries<BR>just aren't quite up to the
task for the average guy--so I made an interim<BR>decision to go back to IC
for the rest of the season--hoping the battery<BR>guys would come up with
something more acceptable for '06.<BR><BR>That didn't pan out very well
either, so I was effectively out for the<BR>season. (Lots of other
contributing factors also) What I told the battery<BR>manufacturer was
what a guy really needs is five sets of batteries(with the<BR>then current
stuff) and immediate service for turnaround. Have three sets<BR>for
flying and one or two sets traveling to/from.<BR><BR>I'm sold on
electric--particularly for a guy with limited practice time.
I<BR>could go on and on....<BR><BR>Richard</TT></FONT> <BR><FONT
face=sans-serif size=2><BR><BR><BR>Gray Fowler<BR>Principal Chemical
Engineer<BR>Composites
Engineering</FONT></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>