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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Yes, my understanding is the pack was peak charged to 4.2v/c and that over a period of 3 to 4 month later (winter) the pack had puffed and the voltage of one cell increased to ~5.0v/c.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>We didn’t discuss how it was stored with regard to physical storage; such as…exposure to extreme heat, cold, etc… they are unknowns…<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>He has been in the battery business for a long time (prior to LiPos gaining popularity in RC) and a long time RC guy who is very active with electric RC and continues to push the limit on electric motor systems and the batteries packs.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Ihncheol [mailto:pnahobbies@sbcglobal.net] <br><b>Sent:</b> Thursday, May 16, 2013 12:17 PM<br><b>To:</b> Larry Diamond; General pattern discussion<br><b>Cc:</b> pnahobbies@sbcglobal.net<br><b>Subject:</b> RE: [NSRCA-discussion] LiPo Storage Voltage Question<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Larry,<o:p></o:p></p></div><div><p class=MsoNormal>I've never had a pack that actually had the voltage rising above charged 4.2v per cell.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Is he telling you voltage increases if the pack was stored in lipo charge bag, fully charged?<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Not something that I am aware of using lipo for past 9 years.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><div><p class=MsoNormal><span style='font-size:9.0pt;color:#575757'>Sent from my Samsung Galaxy Note® II<o:p></o:p></span></p></div></div><p class=MsoNormal style='margin-bottom:12.0pt'><br><br><br>-------- Original message --------<br>From: Larry Diamond <<a href="mailto:ldiamond@diamondrc.com">ldiamond@diamondrc.com</a>> <br>Date: 05/16/2013 11:57 AM (GMT-06:00) <br>To: General pattern discussion <<a href="mailto:nsrca-discussion@lists.nsrca.org">nsrca-discussion@lists.nsrca.org</a>> <br>Subject: [NSRCA-discussion] LiPo Storage Voltage Question <br><br><o:p></o:p></p><div><div><p class=MsoNormal style='background:white'><span style='color:black'>A few days ago this was a topic dicussed at length about LiPo charging and storage practice.<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'> <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'>I learned a bit and thanks to all the posts sheading light on the topic...<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'> <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'>One question that I asked my local battery guy rewarded me with a response I didn't expect. Has anybody else observed this?<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'> <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'>Here is his claim/actual observation:<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'> <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><em><b><u><span style='color:black'>"If a LiPo is stored after a peak charge the voltage may tend to rise over time to as much as 5.0V+ for a single cell."</span></u></b></em><span style='color:black'><o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'> <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'>After the discussion topic on here and discussing the issue with my battery guy, I have came to the conclusion that storing a LiPo battery is much safer at a lower voltage state (~3.9V/Cell) to prevent an inadvertant puff due to an unstable cell(s) climbing voltage over time. I recall the discussion about an unstable pack, but I don't recall any mention of the voltage climbing. Perhaps I missed it and it seems worth revisiting anyway.<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'> <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'>Basically any LiPo battery stored over a 2 week period should be charged/discharged to a storage voltage or a nominal 3.9v/cell. Storage voltage opinons vary from 50%+ (~3.9v/cell+)<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'> <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'>Internet references show 50% charge = nominal 3.85V/cell)<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'> <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'>Additional thoughts on the peaked battery increasing in voltage over a longer period of time...???????????<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'> <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'>I just bought six new 5s-LiPo Packs and I'm new to this stuff... So what say you experienced folks?<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'> <o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'>Larry Diamond<o:p></o:p></span></p></div><div><p class=MsoNormal style='background:white'><span style='color:black'> <o:p></o:p></span></p></div></div></div></body></html>