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<DIV><FONT face=Arial>Jerry:</FONT></DIV>
<DIV><FONT face=Arial>Using A123 batteries requires extra vigilance, since they
have a very flat discharge curve for most of their capacity (after an initial
quick drop), right up to the point where you have little usable capacity
left. As a result, you won't be able to gauge remaining capacity with a
meter, although you can estimate it once you can experience with typical
discharge characteristics. As long as everything with your servo current
drain remains consistent and healthy, you can pick a reasonable quitting point
after X flights. I'm not sure what the appeal of these batteries is for a
flight pack application. One drawback is that you run the servos at a fairly
high voltage, which might damage some servos. If you add
regulators, that problem is alleviated, but overall you have a
heavier solution than with a LiPo set. Enhanced charging safety is really
all that you are buying. </FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>I think the thing that should be realized is that a set of
2 cell 480 or 730 mAh LiPo's have an extraordinarily easy life when all they are
doing is powering a flight pack. You can get many more cycles out of then
than NiCad or NiMH packs and they have much better end of life
performance. I just don't see what the concern is.</FONT></DIV>
<DIV> </DIV>
<DIV>Ed</DIV>
<DIV> </DIV>
<DIV>----- Original Message ----- </DIV>
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<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=jjvoth@mtelco.net href="mailto:jjvoth@mtelco.net">Jerry Voth</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">General pattern discussion</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, February 14, 2009 4:11
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] Receiver
packs</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial>Richard, </FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>I was thinking more about using A-123 batteries. They're
supposed to be safer. My memory is what scares me about Lipos. </FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Also, what would the effect be on an ESC using A-123
batteries in place of Lipos? I've read there are some issues. </FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Jerry</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=pamrich47@hotmail.com href="mailto:pamrich47@hotmail.com">Richard
Strickland</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">General pattern
discussion</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, February 14, 2009 12:37
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion]
Receiver packs</DIV>
<DIV><BR></DIV>Jerry--just a couple thoughts: I will probably never
use a battery for a receiver/flight pack again that I haven't been in
charge of its history. If you've been paying attention to its
characteristics since new, we can generally tell when they start to lose
capacity--and for me, there was a point on the ESV when it got there, I
got a little nervous about going up 'one more time'. When it would
approach that point after about five flights, then I would figure it
was 1. if early in its career--then to cycle and 2. if in to the second or
third year(sometimes longer) it was time to retire it. Nicads for
me have been pretty reliable that way and I've been comfortable running one
pack. You can still go to five cells in nicads for additional capacity
and power with a regulator and still have that reliability. I think
most of the guys that have gone to lipos can enjoy the increased capacity
and power along with an increased discharge rate in a smaller, lighter
package. But I don't get the impression that they trust them like
nicads. Probably the best thing to do is monitor your batteries
of any type with a good, loaded ESV to keep an eye out for any unusual
battery behavior. The two battery debate is a little like the single
versus twin debate in full scale airplanes--some guys think twins just have
double the chances to fail.<BR>All that said, I understand some of the new
receivers are a little touchy regarding low voltage situations. I had
an older receiver in an airplane that I bought used with a 'new'
battery--turned out the battery was bad--but got a warning(hold) and was
able to land--but showed NO volts afterward. <BR>Chances are with the newer
stuff, it may not have made it back on the ground in one piece.
So using a 5 cell nicad or 2 cell lipo with regulator may not be a bad idea
and monitor with a good loaded ESV.<BR>FWIW<BR>Richard<BR> <BR>
<HR id=stopSpelling>
From: jjvoth@mtelco.net<BR>To: nsrca-discussion@lists.nsrca.org<BR>Date:
Fri, 13 Feb 2009 20:32:46 -0600<BR>Subject: Re: [NSRCA-discussion] Receiver
packs<BR><BR>
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<DIV><FONT face=Arial size=2>Thanks for the info guys</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=vicenterc@comcast.net href="mailto:vicenterc@comcast.net">Vicente
"Vince" Bortone</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">General pattern
discussion</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Friday, February 13, 2009 8:28
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion]
Receiver packs</DIV>
<DIV><BR></DIV>
<DIV style="FONT-SIZE: 12pt; COLOR: #000000; FONT-FAMILY: Arial">Hi
Jerry,<BR> <BR>I have been using two li-po using the
tech-aero double regulator <A
href="http://www.tech-aero.net/plr5-dr2.htm">http://www.tech-aero.net/plr5-dr2.htm</A>
The capacity I am using now is 930 mah, 2 cells
batteries. I know that I can fly at least 6-8 times.
After that, I am brain dead.<BR> <BR>VB<BR> <BR><BR>-----
Original Message -----<BR>From: "Richard Strickland" <<A
href="mailto:pamrich47@hotmail.com">pamrich47@hotmail.com</A>><BR>To:
"General pattern discussion"
<nsrca-discussion@lists.nsrca.org><BR>Sent: Friday, February 13,
2009 8:01:03 PM GMT -06:00 US/Canada Central<BR>Subject: Re:
[NSRCA-discussion] Receiver packs<BR><BR>
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Jerry, I think the short answer is no. But there has been much
discussion regarding dual packs for back-up. An example ot single
pack usage is using a 2 cell lipo at around 780-800ma for practice and
340-380ma for contests to make weight. These are used with voltage
regulators with variing outputs.<BR>RS<BR> <BR>> From:
jjvoth@mtelco.net<BR>> To: nsrca-discussion@lists.nsrca.org<BR>>
Date: Fri, 13 Feb 2009 17:32:25 -0600<BR>> Subject: Re:
[NSRCA-discussion] Receiver packs<BR>> <BR>> Sorry, I said that
wrong. I meant are two packs needed to power the flight <BR>>
pack.<BR>> ----- Original Message ----- <BR>> From: "Jerry Voth"
<jjvoth@mtelco.net><BR>> To: "NSRCA"
<nsrca-discussion@lists.nsrca.org><BR>> Sent: Friday, February
13, 2009 5:23 PM<BR>> Subject: [NSRCA-discussion] Receiver
packs<BR>> <BR>> <BR>> > This has probably come up many times
but I'd like to know if it's <BR>> > necessary<BR>> > to use
two Li-Fe packs for the radio and servos<BR>> >
_______________________________________________<BR>> >
NSRCA-discussion mailing list<BR>> >
NSRCA-discussion@lists.nsrca.org<BR>> >
http://lists.nsrca.org/mailman/listinfo/nsrca-discussion<BR>>
><BR>> <BR>> <BR>>
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