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<DIV dir=ltr align=left><SPAN class=761402208-18092008><FONT face=Arial
size=2>Oh, .. . I'm off fishing.... I will have the charger when I get back on
Sunday.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=761402208-18092008><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=761402208-18092008><FONT face=Arial
size=2>sc</FONT></SPAN></DIV><BR>
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<FONT face=Tahoma size=2><B>From:</B> nsrca-dist7-bounces@lists.nsrca.org
[mailto:nsrca-dist7-bounces@lists.nsrca.org] <B>On Behalf Of </B>krishlan
fitzsimmons<BR><B>Sent:</B> Wednesday, September 17, 2008 10:22 PM<BR><B>To:</B>
CA, AZ, HI, NV, UT<BR><B>Subject:</B> Re: [NSRCA-dist7] LiPo cell
configuration<BR></FONT><BR></DIV>
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<TD vAlign=top>I remember this conversation from the contest. Glad you
brought this up. I'm curious to know how my bad packs test out. I may have
to get a cell pro. Mine are 1p's and I like them that way. Less cells can
go bad in my way of thinking. <BR>As I sit here contemplating the fact
that I need to buy new batteries, this is very interesting to me. It's
also interesting that the TrueRc packs that I have been considering,
possibly aren't getting as good of reviews after people have several
flights on them. Not sure why. I'm sure the cell chemistry is
similar to others. I'm pretty baffled at what packs to buy. I'm still
leaning towards the TrueRc as I figure if they get me 100 cycles a set,
then I pay like 2.50 per flight. Similar to glow. And I probably fly about
100-150"pattern" flights a year (yes, I know, I need more practice) lol.
So spending 250-350 per year on batteries is fine with me. <BR>I sure do
know that my $2300 that I bought last year are shot at this point because
of my charger that I was using. <BR>Taking my 2 good set's to the field in
the morning to fly, well, 2 flights. lol.. <BR><BR>Interesting topic here.
<BR><BR>
<DIV><STRONG><EM><FONT face="comic sans ms" color=#0000bf size=3>Chris
</FONT></EM></STRONG></DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV> </DIV><BR><BR>--- On <B>Wed, 9/17/08, Scott
<I><scottcov@comcast.net></I></B> wrote:<BR>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: rgb(16,16,255) 2px solid">From:
Scott <scottcov@comcast.net><BR>Subject: [NSRCA-dist7] LiPo cell
configuration<BR>To: dist7@nsrca.org<BR>Date: Wednesday, September 17,
2008, 9:04 PM<BR><BR>
<DIV id=yiv13735875>
<DIV><SPAN class=279212203-18092008><FONT face=Arial size=2>Hey Electric
Guys,</FONT></SPAN></DIV>
<DIV><SPAN class=279212203-18092008><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=279212203-18092008><FONT face=Arial size=2>I'd be
interested in what LiPo battery configuration you are using.. 5S2P,
5S4P, 5S1P... other. Why?.. read on. I believe the less "P" you have in
the battery the easier to balance and possibly the longer life you will
get due to better cell balancing before charging. I have recently
converted to a new cell by TP, some of you saw this at the Hollister
contest. The 5S2P, 5200 pack, is working great. Jim Oddino and I checked
the internal cell resistance, which was around 3milli-ohms (if I recall
correctly). This battery puts out 156A burst, the older 5s4p, 5300 pack
put out 109A burst. My thinking is this, the lower "P" pack you have the
easier to keep the battery in balance. If you have a 4p pack, any one of
the 4p cells can degrade over time, causing the 4p 'bank' to not supply
as much sustained current - causing the whole battery to be weaker. Jim
and I played with a Cellpro 10S charger, and I think we concluded that
it would be difficult for any charger to determine if any one cell
in a 4p bank was going bad (you can only monitor the bank IR, not
the individual cell within the bank). However, if you had a 1p 10S pack,
you could easily tell if the cell was gaining resistance as it aged. On
a 2p pack, the resistance CHANGE may not show up as easily as a 1p pack
but much easier than a 4p pack. We are trying to determine here when a
5S pack is getting weak (yes, we can see as we fly - but if we could
determine as it happens, perhaps we can correct this by charging
differently). Jim O mentions he has not seen a battery with as low of
internal resistance readings as the new TP pack, which equates to more
power, less heat in use, and I hope longer life. I will mention
here that my 5300, 5s4p packs have lasted 2-3 years and many,
many flights, but they are getting old.. and the new packs may
last 3-4 years.. they are also around $250 each.. a reduction in price
from the 5s4p packs. I believe even newer technology will soon show us a
10s1p pack from TP - and some may have this now from other
manufacturers.</FONT></SPAN></DIV>
<DIV><SPAN class=279212203-18092008><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=279212203-18092008><FONT face=Arial size=2>I'd be
interested in your opinions on this topic.</FONT></SPAN></DIV>
<DIV><SPAN class=279212203-18092008><FONT face=Arial
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=279212203-18092008><FONT face=Arial
size=2>Scott</FONT></SPAN></DIV>
<DIV><SPAN class=279212203-18092008><FONT face=Arial
size=2></FONT></SPAN> </DIV></DIV><PRE>_______________________________________________<BR>NSRCA-dist7 mailing list<BR>NSRCA-dist7@lists.nsrca.org<BR>http://lists.nsrca.org/mailman/listinfo/nsrca-dist7<BR></PRE></BLOCKQUOTE></TD></TR></TBODY></TABLE><BR></BODY></HTML>