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<DIV>Do we need to balance this batteries? </DIV>
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<DIV>Thanks,</DIV>
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<DIV class=signature id=signature>--<BR>Vicente "Vince" Bortone</DIV>
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<BLOCKQUOTE style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">-------------- Original message -------------- <BR>From: "brett terry" <brett.terry@gmail.com> <BR>The VPX cells are indeed actual A123 cells. They are roughly half the size/capability/capacity of the larger cells, expect around 1000 mAh usable with minimal voltage depression at 10C discharge. The pack consists of 2 cells in series (2S).<BR><BR>Use the Li-Fe setting (3.6V/cell) to charge. <BR><BR>I built a few of the larger packs for my IMAC planes and threw together a smaller pack for ignition, and also a 4S pack for electric planes. They are fabulous in terms of actual power output throughout the discharge cycle because the voltage remains nearly constant. I can draw 20C current levels from a deeply discharged pack, right up until they dump. Of course they dump VERY fast, so a lot of care is required. My charger shows the remaining charge state (from 0
% to 100%) when I plug in the battery (BEFORE it charges). I just plug in the charger after a couple of flights and if the remaining charge is under 30%, I just leave it on the charger for a few minutes to top it off. These small batteries will charge from completely dead to fully charged in less than 20 minutes, although they go to 95% of charge after 7-10 minutes. I find I can plug them in while refueling the plane to keep them topped off.<BR><BR>Also, my 50cc planes with big servos draw around 250-350 mAh per flight or less, so a pattern plane will draw significantly less. Check out Bob Pastorello's site (<A href="http://www.rcaerobats.net/">www.rcaerobats.net</A>) or RCU/FG for more info. <BR><BR>
<DIV class=gmail_quote>On Feb 19, 2008 12:54 PM, John Konneker <<A href="mailto:jlkonn@hotmail.com">jlkonn@hotmail.com</A>> wrote:<BR>
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<DIV>I was just in WalMart. They had the B&D 7v VPX battery packs for $17.88. I believe these are A123. If that is correct what chemsitry should I select on my BC-6 charger? I have three ID'd as Lithium:<BR>- Li-Ion shown as max charge 4.1v/cell<BR>- Li-Po shown as max charge 4.2v/cell<BR>- Li-Fe shown as max charge 3.6v/cell<BR>The plastic case it's in is about 3 3/4" long and 1 3/4" wide. This seems long. Is this pack 2s2p? Anyone taken these apart to build a receiver pack?<BR>To determine capacity what voltage should the cycle cutoff be set at?<BR>Thanks!<BR>JLK<BR></DIV></DIV></DIV><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" target=_blank>http://lists.nsrca.org/mailman/listinfo/nsrca-discussion</A><BR></BLOCKQUOTE></DIV><BR></BLOCKQUOT
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