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<DIV>My experience last year was very similar to Earl's experience. If you ask me today, I won't use for electric pattern (Master and F3A schedules) less than 5300 mah capacity. </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: "Earl Haury" <ejhaury@comcast.net> <BR><BR>> Chad, you have a point, however it's important to factor in that the 1P <BR>> packs are also generally higher C rating. My view when considering batteries <BR>> initially was that higher cell count provided more failure opportunities, <BR>> both as individual cell failure and connections. I've disassembled a number <BR>> of "failed", or no longer pattern suitable packs, and measured individual <BR>> cell characteristics. <BR>> <BR>> Generally, the cells in a lower C pack tend demonstrate an increase in <BR>> impedance, resulting in lower voltage output for a given current draw over <BR>> their lifespan until no longer "pattern viable". During this time capacity <BR>> diminishes - but most cells with high impedance will still retain 80+% of <BR>> their or
iginal capacity. Even though these things generate more heat than <BR>> the higher C packs - they tend to handle abuse (as you've found) partly <BR>> because of the retained capacity and partly because of "performance <BR>> limiting" impedance. Post flight imbalance doesn't change too much as these <BR>> packs age - suggesting a similar "aging" of the individual cells. <BR>> <BR>> Conversely, the high C packs demonstrate very low impedance initially and <BR>> that appears to be retained throughout their life. However, the cell <BR>> capacity appears to drop pretty early and continue to do so over the pack <BR>> life. I've measured some of these with an average capacity loss of 40% after <BR>> 50 flights - that means a 5000 mAh pack is now a 3000 mAh pack. Even worse - <BR>> there is often a good deal of variance from cell to cell. Their low <BR>> impedance will provide little warning (as loss of power) until a cell is <BR>> injured, real easy
to do if you try to take 3500 mAh from the now 3000 pack. <BR>> Often one will notice the post flight imbalance increasing as these packs <BR>> age and it will be greater at higher depths of discharge - a sure sign some <BR>> cells are getting weak. OTOH - for blazing power the high C packs are the <BR>> way to go - but there's a price to pay in life, weight, & $$. <BR>> <BR>> These observations have led me to surmise that a pack with a high enough C <BR>> rating to minimize impedance losses (and accompanying heat) and a low enough <BR>> C rating to allow good capacity retention should provide the best value for <BR>> pattern. I have no idea just what construction parameters / chemistry <BR>> defines these characteristics. I chose to try the FlightPower F3A packs <BR>> because they are mid-C rating and 5350 mAh capacity. So far they provide <BR>> good power and generate no more heat than the high C packs I've used. I <BR>> expect that the
extra capacity (above 5000) offers a little buffer if there <BR>> is a capacity decline over their life. I see little balancer activity with <BR>> these packs regardless of depth of discharge (say 3000 mAh vs 4000 +) so <BR>> far, time will tell - we're all still learning. <BR>> <BR>> Earl <BR>> <BR>> Team FlightPower <BR>> <BR>> <BR>> ----- Original Message ----- <BR>> From: "Chad Northeast" <CHAD@F3ACANADA.ORG><BR>> To: "NSRCA Mailing List" <NSRCA-DISCUSSION@LISTS.NSRCA.ORG><BR>> Sent: Friday, March 14, 2008 8:22 AM <BR>> Subject: Re: [NSRCA-discussion] Batteries <BR>> <BR>> <BR>> >I think a huge part of the 5300 Prolites ability to deliver under <BR>> > extreme abuse (I should know! :) ) is in large part due to a 4p config <BR>> > rather than 1p as in the current packs. In a 1p when that cell gets <BR>> > weak its over, in a 4p when a cell gets weak the other 3 in the 4p can <BR>> > help it along for q
uite a while before they all get weak. <BR>> > <BR>> > I am really convinced that a move to 1p config packs has brought with it <BR>> > lower useful cycle life. I feel you need to be a lot more cautious with <BR>> > the 1p packs than the 4p's, or they will not last you very long :) <BR>> > <BR>> > Chad <BR>> > <BR>> > mike mueller wrote: <BR>> >> Chris Moon and I have bought the new TrueRC 5000 packs. He has been <BR>> >> testing them for the last 2 months. They seem as strong if not <BR>> >> stronger than his FP 5350 pack. The cost is only $110 a 5S pack. I've <BR>> >> bought 4 packs and I'm hoping that they are as good as initial testing <BR>> >> has shown. I also have 2 brand new TP V2 Extreme 10S 5000 packs. All <BR>> >> the packs at the 10S configuration weigh in around 42oz's with all the <BR>> >> connectors. <BR>> >> The True RC packs have a lower C rating
but this may be a good thing. <BR>> >> The higher C ratings seem to come at the cost of lower pack life. Look <BR>> >> at the TP Pro lite's many have exceeded the 200 cycle barrier and <BR>> >> still have a decent pack. The TP Extreme's V1's were dying in 50 <BR>> >> flights and I have yet to see much better than a hundred flights from <BR>> >> the FP's. From my observation the older TP Prolites deliver plenty of <BR>> >> power for our setups. So I think the TrueRC offerings are going to do <BR>> >> the trick. Dan from True is claiming over 200 cycles on them. I hope <BR>> >> that I can get 100. At the $'s he's getting it will be a huge bargain. <BR>> >> Mike Mueller <BR>> >> <BR>> >> The link is www.flightpowerusa.com <HTTP: www.flightpowerusa.com /><BR>> >> <BR>> >> I need to buy some packs myself. Anybody know if they will be at <BR>> >> Toledo? <BR>>
>> <BR>> >> Bob Kane <BR>> >> getterflash@yahoo.com <BR>> >> <BR>> >> <BR>> >> ----- Original Message ---- <BR>> >> From: Verne Koester <VERNE@TWMI.RR.COM><BR>> >> To: NSRCA Mailing List <NSRCA-DISCUSSION@LISTS.NSRCA.ORG><BR>> >> Sent: Thursday, March 13, 2008 6:58:32 PM <BR>> >> Subject: Re: [NSRCA-discussion] Batteries <BR>> >> <BR>> >> Hi George, <BR>> >> I'm in the same situation and have decided to go with the FlightPower <BR>> >> 5350's. Even when the 5300's were fresh, I occasionally felt like <BR>> >> I could <BR>> >> use a little more punch, particularly on humid or windy days. I've <BR>> >> competed <BR>> >> with a number of guys that had both the TP 5300's and FP 5350's <BR>> >> who would <BR>> >> switch to the 5350's when they needed the extra power. My plan is <BR>> >> to use the <BR>&g
t; >> FP 5350's and change props for different conditions. Nothing is <BR>> >> free however <BR>> >> and you'll pick up 2 ounces in the process. I considered the 5000 <BR>> >> mah 10S <BR>> >> packs from both TP and FP but can't afford to gain 4 ounces in <BR>> >> either of my <BR>> >> existing planes. The FP 5350's are the best solution for my <BR>> >> situation. Mine <BR>> >> just arrived this week and won't be flown until the snow melts so my <BR>> >> recommendations come from observations rather than experience at <BR>> >> this point. <BR>> >> I bought mine directly from FlightPower <BR>> >> http://www.flightpower.com <HTTP: www.flightpower.com />. Hope <BR>> >> this helps. <BR>> >> <BR>> >> Verne Koester <BR>> >> <BR>> >> <BR>> >> ----- Original Message ----- <BR>> >> From: <GLMILLER3@SUDDENLINK.NET <ma
ilto:glmiller3@suddenlink.net>> <BR>> >> To: "NSRCA List" <NSRCA-DISCUSSION@LISTS.NSRCA.ORG <BR>> >> <mailto:nsrca-discussion@lists.nsrca.org>> <BR>> >> Sent: Thursday, March 13, 2008 12:26 PM <BR>> >> Subject: [NSRCA-discussion] Batteries <BR>> >> <BR>> >> <BR>> >> > Hi All, <BR>> >> > <BR>> >> > I've been flying with Thunder Power Prolite 5300 packs for a <BR>> >> while now and <BR>> >> > they are getting very tired. As they poop out, I'm trying to <BR>> >> decide what <BR>> >> > to replace them with. From what I've seen, the Flightpower <BR>> >> "FAI" packs <BR>> >> > are probably what I'll go with, but if anyone has any other <BR>> >> suggestions, <BR>> >> > please sing out. Also, any suggestions as to a source would be <BR>> >> > appreciated. <BR>> >> > <BR>> >> >
TIA, <BR>> >> > <BR>> >> > George <BR>> >> > _______________________________________________ <BR>> >> > NSRCA-discussion mailing list <BR>> >> > NSRCA-discussion@lists.nsrca.org <BR>> >> <mailto:NSRCA-discussion@lists.nsrca.org><BR>> >> > http://lists.nsrca.org/mailman/listinfo/nsrca-discussion <BR>> >> > <BR>> >> <BR>> >> <BR>> >> _______________________________________________ <BR>> >> NSRCA-discussion mailing list <BR>> >> NSRCA-discussion@lists.nsrca.org <BR>> >> <mailto:NSRCA-discussion@lists.nsrca.org><BR>> >> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion <BR>> >> <BR>> >> <BR>> >> ------------------------------------------------------------------------ <BR>> >> Looking for last minute shopping deals? Find them fast with Yahoo! <BR>> >> Search. <BR>> >> <BR>&
gt; >> <BR>> <HTTP: <BR evt="51734/*http://tools.search.yahoo.com/newsearch/categ" us.rd.yahoo.com>> ory.php?category=shopping>_______________________________________________ <BR>> >> NSRCA-discussion mailing list <BR>> >> NSRCA-discussion@lists.nsrca.org <BR>> >> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion <BR>> >> <BR>> >> <BR>> >> ------------------------------------------------------------------------ <BR>> >> Never miss a thing. Make Yahoo your homepage. <BR>> >> <HTTP: evt="51438/*http://www.yahoo.com/r/hs" us.rd.yahoo.com><BR>> >> ------------------------------------------------------------------------ <BR>> >> <BR>> >> _______________________________________________ <BR>> >> NSRCA-discussion mailing list <BR>> >> NSRCA-discussion@lists.nsrca.org <BR>> >> http://lists.nsrca.org/mailman/listinfo/nsrca-discussion <BR>> >
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