<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">I'll second that. I see a bunch of folks that are not near as knowledgeable as pattern folk flying all kinds of aircraft and they don't seem to have problems with LiPos. I believe the loss of planes due to NiCds and NiMHs was/is a lot higher than those lost to Lithiums (excluding those early Duralites).<div><br></div><div>Jim O</div><div><br></div><div><br><div><div>On Feb 14, 2009, at 1:26 PM, Ed Alt wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0; "><div class="hmmessage" bgcolor="#ffffff" style="font-size: 10pt; font-family: Verdana; "><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><blockquote style="padding-right: 0px; padding-left: 5px; margin-left: 5px; border-left-color: rgb(0, 0, 0); border-left-width: 2px; border-left-style: solid; margin-right: 0px; "><div style="background-image: initial; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: rgb(228, 228, 228); font: normal normal normal 10pt/normal arial; background-position: initial initial; "><b>From:</b><span class="Apple-converted-space"> </span><a title="jjvoth@mtelco.net" href="mailto:jjvoth@mtelco.net">Jerry Voth</a></div><div style="font: normal normal normal 10pt/normal arial; "><b>To:</b><span class="Apple-converted-space"> </span><a title="nsrca-discussion@lists.nsrca.org" href="mailto:nsrca-discussion@lists.nsrca.org">General pattern discussion</a></div><div style="font: normal normal normal 10pt/normal arial; "><b>Sent:</b><span class="Apple-converted-space"> </span>Saturday, February 14, 2009 4:11 PM</div><div style="font: normal normal normal 10pt/normal arial; "><b>Subject:</b><span class="Apple-converted-space"> </span>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-color: rgb(0, 0, 0); border-left-width: 2px; border-left-style: solid; margin-right: 0px; "><div style="font: normal normal normal 10pt/normal arial; ">----- Original Message -----</div><div style="background-image: initial; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: rgb(228, 228, 228); font: normal normal normal 10pt/normal arial; background-position: initial initial; "><b>From:</b><span class="Apple-converted-space"> </span><a title="pamrich47@hotmail.com" href="mailto:pamrich47@hotmail.com">Richard Strickland</a></div><div style="font: normal normal normal 10pt/normal arial; "><b>To:</b><span class="Apple-converted-space"> </span><a title="nsrca-discussion@lists.nsrca.org" href="mailto:nsrca-discussion@lists.nsrca.org">General pattern discussion</a></div><div style="font: normal normal normal 10pt/normal arial; "><b>Sent:</b><span class="Apple-converted-space"> </span>Saturday, February 14, 2009 12:37 PM</div><div style="font: normal normal normal 10pt/normal arial; "><b>Subject:</b><span class="Apple-converted-space"> </span>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.<span class="Apple-converted-space"> </span><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:<span class="Apple-converted-space"> </span><a href="mailto:jjvoth@mtelco.net">jjvoth@mtelco.net</a><br>To:<span class="Apple-converted-space"> </span><a href="mailto:nsrca-discussion@lists.nsrca.org">nsrca-discussion@lists.nsrca.org</a><br>Date: Fri, 13 Feb 2009 20:32:46 -0600<br>Subject: Re: [NSRCA-discussion] Receiver packs<br><br><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-color: rgb(0, 0, 0); border-left-width: 2px; border-left-style: solid; margin-right: 0px; "><div style="font: normal normal normal 10pt/normal arial; ">----- Original Message -----</div><div style="background-image: initial; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: rgb(228, 228, 228); font: normal normal normal 10pt/normal arial; background-position: initial initial; "><b>From:</b><span class="Apple-converted-space"> </span><a title="vicenterc@comcast.net" href="mailto:vicenterc@comcast.net">Vicente "Vince" Bortone</a></div><div style="font: normal normal normal 10pt/normal arial; "><b>To:</b><span class="Apple-converted-space"> </span><a title="nsrca-discussion@lists.nsrca.org" href="mailto:nsrca-discussion@lists.nsrca.org">General pattern discussion</a></div><div style="font: normal normal normal 10pt/normal arial; "><b>Sent:</b><span class="Apple-converted-space"> </span>Friday, February 13, 2009 8:28 PM</div><div style="font: normal normal normal 10pt/normal arial; "><b>Subject:</b><span class="Apple-converted-space"> </span>Re: [NSRCA-discussion] Receiver packs</div><div><br></div><div style="font-size: 12pt; color: rgb(0, 0, 0); font-family: Arial; ">Hi Jerry,<br> <br>I have been using two li-po using the tech-aero double regulator<span class="Apple-converted-space"> </span><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" <<a href="mailto:nsrca-discussion@lists.nsrca.org">nsrca-discussion@lists.nsrca.org</a>><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>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:<span class="Apple-converted-space"> </span><a href="mailto:jjvoth@mtelco.net">jjvoth@mtelco.net</a><br>> To:<span class="Apple-converted-space"> </span><a href="mailto:nsrca-discussion@lists.nsrca.org">nsrca-discussion@lists.nsrca.org</a><br>> Date: Fri, 13 Feb 2009 17:32:25 -0600<br>> Subject: Re: [NSRCA-discussion] Receiver packs<br>><span class="Apple-converted-space"> </span><br>> Sorry, I said that wrong. I meant are two packs needed to power the flight<span class="Apple-converted-space"> </span><br>> pack.<br>> ----- Original Message -----<span class="Apple-converted-space"> </span><br>> From: "Jerry Voth" <<a href="mailto:jjvoth@mtelco.net">jjvoth@mtelco.net</a>><br>> To: "NSRCA" <<a href="mailto:nsrca-discussion@lists.nsrca.org">nsrca-discussion@lists.nsrca.org</a>><br>> Sent: Friday, February 13, 2009 5:23 PM<br>> Subject: [NSRCA-discussion] Receiver packs<br>><span class="Apple-converted-space"> </span><br>><span class="Apple-converted-space"> </span><br>> > This has probably come up many times but I'd like to know if it's<span class="Apple-converted-space"> </span><br>> > necessary<br>> > to use two Li-Fe packs for the radio and servos<br>> > _______________________________________________<br>> > NSRCA-discussion mailing list<br>> ><span class="Apple-converted-space"> </span><a href="mailto:NSRCA-discussion@lists.nsrca.org">NSRCA-discussion@lists.nsrca.org</a><br>> ><span class="Apple-converted-space"> </span><a href="http://lists.nsrca.org/mailman/listinfo/nsrca-discussion">http://lists.nsrca.org/mailman/listinfo/nsrca-discussion</a><br>> ><br>><span class="Apple-converted-space"> </span><br>><span class="Apple-converted-space"> </span><br>> --------------------------------------------------------------------------------<br>><span class="Apple-converted-space"> </span><br>><span class="Apple-converted-space"> </span><br>><span class="Apple-converted-space"> </span><br>> No virus found in this incoming message.<br>> Checked by AVG -<span class="Apple-converted-space"> </span><a href="http://www.avg.com">www.avg.com</a><br>> Version: 8.0.237 / Virus Database: 270.10.23/1951 - Release Date: 02/13/09<span class="Apple-converted-space"> </span><br>> 06:51:00<br>><span class="Apple-converted-space"> </span><br>> _______________________________________________<br>> NSRCA-discussion mailing list<br>><span class="Apple-converted-space"> </span><a href="mailto:NSRCA-discussion@lists.nsrca.org">NSRCA-discussion@lists.nsrca.org</a><br>><span class="Apple-converted-space"> </span><a href="http://lists.nsrca.org/mailman/listinfo/nsrca-discussion">http://lists.nsrca.org/mailman/listinfo/nsrca-discussion</a><br><br><br><hr><div style="padding-right: 0px; 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