<table cellspacing="0" cellpadding="0" border="0" ><tr><td valign="top" style="font: inherit;">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 color="#0000bf" face="comic sans ms" 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="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;">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></table><br>