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<DIV><FONT face=Arial size=2>Keep in mind we're talking about airborne batteries
NOT power system batteries. That's a whole different application. In that case,
balancing is necessary and easily done while you're charging. For my
big power system packs I use a TP1010c charger and a T.P. balancer.
</FONT></DIV>
<DIV><FONT face=Arial size=2> On smaller batteries i still think it's
probably OK to charge without a balancer as long as the charge rate isn't too
high. Usually 1/2C (2 hours) will charge them fine without a balancer. If you're
just topping them up after flying this rate is reasonable.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>John Pavlick<BR><A
href="http://www.idseng.com">http://www.idseng.com</A></FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=jpavlick@idseng.com href="mailto:jpavlick@idseng.com">John
Pavlick</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Sunday, February 24, 2008 11:55
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] Li-Po and
Regulators for 4C applications</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Lance,</FONT></DIV>
<DIV><FONT face=Arial size=2> My experience with LiPOs so far (and I may
be wrong so suggestions are welcome) is that unless you're pushing them hard
(i.e. running an elecetric motor) they don't get out of balance easily. If
you're using a 15 or 20C pack to run the servos in a Pattern plane I
don't think you'll see balance problems. An Astro Blinky would probably be a
good way to balance your packs once in a while - it's
reasonably priced. I really don't think you need to balance while you charge
so the Sirius charger + Blinky combo is fine. The other nice thing about the
Sirius charger is that it has a built in volt meter. </FONT></DIV>
<DIV><FONT face=Arial size=2> The best way to prevent the loss of an
airplane because of a bad switch or battery pack is to use 2 battery packs.
I'm setting up my new airplane with a 2 pack system and 2 of the regulators
that Ed Alt and I make (Tech Aero). Check out our website: <A
href="http://www.tech-aero.net">http://www.tech-aero.net</A> Ed has written a
nice document that describes how to use our regulators in a fail-safe
redundant system. Check it out: <A
href="http://www.tech-aero.net/documents/Tech-Tip%200601.pdf">http://www.tech-aero.net/documents/Tech-Tip%200601.pdf</A></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>John Pavlick<BR><A
href="http://www.idseng.com">http://www.idseng.com</A></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
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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=patterndude@tx.rr.com href="mailto:patterndude@tx.rr.com">Lance Van
Nostrand</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Sunday, February 24, 2008 12:33
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] Li-Po
and Regulators for 4C applications</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>John,</FONT></DIV>
<DIV><FONT face=Arial size=2>That sounds very good. This may be the
answer. After a short internet search it looks like the astro109, and
TP have chargers in the same price range. Some people swear by their
Triton II. There are a lot of more obscure companies making what seem
to be combination chargers or Li chargers that do what I had
requested. your recommendation carries a lot of weight with me.
I'm not sure if balancing is important with a 2S pack but I do have a
passive balancer that can be used after charging. I think Falcon
batteries believes that this is an acceptable way to balance a pack (doesn't
have to be balanced during charging) so if this is correct the Sirius might
be enough. Red Sholefield used to do excellent reviews of NiCd/NimH
chargers but for LiPo's he seems to just recommend FMA
products.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I'd love to hear other peoples recommendations
but only for chargers with displays that can show charging
information. For old-school packs I have 2 Robbe Infinity2 chargers
and they have a pack diagnostic mode that is to die for. It finds
weaknesses in packs that seem to be operating OK. Of course it may be
a random number generator but I decided to run the diagnostic a few times a
year and if it fails a pack I toss it. After losing 4 planes to power
problems a few years ago I think the $18 on a new NimH pack is cheap
insurance if necessary, but I usually get well over a year on a
pack.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>--Lance</FONT></DIV>
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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=jpavlick@idseng.com href="mailto:jpavlick@idseng.com">John
Pavlick</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, February 22, 2008 11:35
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] Li-Po
and Regulators for 4C applications</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Lance,</FONT></DIV>
<DIV><FONT face=Arial size=2> The Sirius Lithium charger tells you
how much energy has gone back into the battery as well as showing what the
charge current is and also if it's in constant current or constant voltage
mode. That should be enough for you to figure out if it really charged the
battery or not.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>John Pavlick<BR><A
href="http://www.idseng.com">http://www.idseng.com</A></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
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face=Arial size=2></FONT> </BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE>
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