<HTML xmlns:o><HEAD></HEAD>
<BODY
style="WORD-WRAP: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space"
dir=ltr>
<DIV dir=ltr>
<DIV style="FONT-SIZE: 12pt; FONT-FAMILY: 'Calibri'; COLOR: #000000">
<DIV>Naught -N- Naught equals Naught . . . .</DIV>
<DIV>.</DIV>
<DIV>.</DIV>
<DIV>Seven Gazinta Twenty-One Thrice . . .</DIV>
<DIV>.</DIV>
<DIV> </DIV>
<DIV
style="FONT-SIZE: small; FONT-FAMILY: 'Calibri'; FONT-WEIGHT: normal; COLOR: #000000; FONT-STYLE: normal; TEXT-DECORATION: none; DISPLAY: inline">
<DIV style="FONT: 10pt tahoma">
<DIV> </DIV>
<DIV style="BACKGROUND: #f5f5f5">
<DIV style="font-color: black"><B>From:</B> <A title=vanputter@gmail.com
href="mailto:vanputter@gmail.com">Ronald Van Putte</A> </DIV>
<DIV><B>Sent:</B> Wednesday, May 08, 2013 6:10 PM</DIV>
<DIV><B>To:</B> <A title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">General pattern discussion</A>
</DIV>
<DIV><B>Subject:</B> Re: [NSRCA-discussion] Battery discharge/storage
question</DIV></DIV></DIV>
<DIV> </DIV></DIV>
<DIV
style="FONT-SIZE: small; FONT-FAMILY: 'Calibri'; FONT-WEIGHT: normal; COLOR: #000000; FONT-STYLE: normal; TEXT-DECORATION: none; DISPLAY: inline">No
so youngster! What I told you was that I didn't think you could handle it.
<DIV> </DIV>
<DIV>Ron</DIV>
<DIV>
<DIV> </DIV>
<DIV>
<DIV>On May 8, 2013, at 2:17 PM, Keith Hoard wrote:</DIV><BR
class=Apple-interchange-newline>
<BLOCKQUOTE type="cite">
<DIV>
<DIV>Van Putte told me there would be no math. <BR><BR>Sent from my
iPhone</DIV>
<DIV><BR>On May 8, 2013, at 13:46, "Dave Harmon" <<A
href="mailto:k6xyz@sbcglobal.net">k6xyz@sbcglobal.net</A>>
wrote:<BR><BR></DIV>
<BLOCKQUOTE type="cite">
<DIV>
<META name=Generator content="Microsoft Word 12 (filtered medium)">
<STYLE><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
@font-face
{font-family:"Comic Sans MS";
panose-1:3 15 7 2 3 3 2 2 2 4;}
/* Style Definitions */
p.msonormal, li.msonormal, div.msonormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.msohyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.msohyperlinkfollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.emailstyle17
{mso-style-type:personal-reply;
font-family:"Comic Sans MS";
color:#1f497d;
font-weight:normal;
font-style:normal;}
.msochpdefault
{mso-style-type:export-only;}
@page wordsection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.wordsection1
{page:wordsection1;}
--></STYLE>
<DIV class=WordSection1>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d"><o:p></o:p></SPAN> </P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">At the
end of every flying session, I leave the field with the batteries in
whatever state of charge that they have.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">I
don’t do a storage charge at the field.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">I do
the storage charge at home.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d"><o:p></o:p></SPAN> </P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">If I
am going to fly the next day or in a few days….less than a week, I do not
discharge the already charged batteries….but I DO top them off at the field
the next time out.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">Today’s
chargers usually go into the balance mode immediately when charging a
previously charged battery so I don’t believe there is a problem topping off
a previously charged battery.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d"><o:p></o:p></SPAN> </P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">Before
I leave for the field, I charge all batteries that are discharged or in
storage charge.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">If I
have several flying sessions in a week or so I will NOT put any discharged
batteries in storage charge….<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">Then I
charge them just before I leave home on the next day I go
flying.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">If I
know I am not going to fly for several days then I DO put discharged
batteries in storage charge….AND discharge charged batteries low enough to
put into storage charge.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d"><o:p></o:p></SPAN> </P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d"><o:p></o:p></SPAN> </P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">If I
need to discharge any batteries I do it with a 17 ohm 100w Dale
resistor.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">I made
a 12” heavy zip cord lead with alligator clips on one end and a matching
connector for the battery on the other end.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">I use
a Fluke DVM across the resistor to monitor the voltage and I discharge down
to about 35 volts.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">Then I
immediately do a storage charge.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">I
might not have to take them down to 35 volts but the battery must be below
the storage charge voltage to get the charger into the storage
mode.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d"><o:p></o:p></SPAN> </P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">If you
do the math….the discharge on a fully charged battery is about 2.4A and the
resistor is running within its wattage range.<o:p></o:p></SPAN></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d"><o:p></o:p></SPAN> </P>
<P class=MsoNormal><B><SPAN
style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">Dave
Harmon<o:p></o:p></SPAN></B></P>
<P class=MsoNormal><B><SPAN
style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">NSRCA
586<o:p></o:p></SPAN></B></P>
<P class=MsoNormal><B><SPAN
style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">K6XYZ[at]sbcglobal[dot]net<o:p></o:p></SPAN></B></P>
<P class=MsoNormal><B><SPAN
style="FONT-SIZE: 10.5pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d">Sperry,
Ok.<o:p></o:p></SPAN></B></P>
<P class=MsoNormal><SPAN
style="FONT-SIZE: 11pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #1f497d"><o:p></o:p></SPAN> </P>
<DIV
style="BORDER-TOP: #b5c4df 1pt solid; BORDER-RIGHT: medium none; BORDER-BOTTOM: medium none; PADDING-BOTTOM: 0in; PADDING-TOP: 3pt; PADDING-LEFT: 0in; BORDER-LEFT: medium none; PADDING-RIGHT: 0in">
<P class=MsoNormal><B><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'Tahoma','sans-serif'">From:</SPAN></B><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: 'Tahoma','sans-serif'"> <A
href="mailto:nsrca-discussion-bounces@lists.nsrca.org">nsrca-discussion-bounces@lists.nsrca.org</A>
[<A
href="mailto:nsrca-discussion-bounces@lists.nsrca.org">mailto:nsrca-discussion-bounces@lists.nsrca.org</A>]
<B>On Behalf Of </B>Scott McHarg<BR><B>Sent:</B> Wednesday, May 08, 2013
1:06 PM<BR><B>To:</B> General pattern discussion<BR><B>Subject:</B> Re:
[NSRCA-discussion] Battery discharge/storage
question<o:p></o:p></SPAN></P></DIV>
<P class=MsoNormal><o:p></o:p> </P>
<DIV>
<P class=MsoNormal>I got scolded not too long ago for even suggesting it by
a ThunderPower rep. I wanted to top off because after a week, one of
my packs had dropped down to like 94% (yes it was an older pack and had a
little over 180 cycles on it). I was told that topping off "could"
cause damage to the packs immediately regardless of age. It was a
fairly stern warning. Honestly, I didn't ask more because I was
already hanging my head from the scolding. I just said "Yes sir,
sir". :)<o:p></o:p></P></DIV>
<DIV>
<P class=MsoNormal style="MARGIN-BOTTOM: 12pt"><o:p></o:p> </P>
<DIV>
<P class=MsoNormal>On Wed, May 8, 2013 at 1:00 PM, Atwood, Mark <<A
href="mailto:atwoodm@paragon-inc.com"
target=_blank>atwoodm@paragon-inc.com</A>> wrote:<o:p></o:p></P>
<P class=MsoNormal>Okay, I'll bite. Why don't you want to top off the
charge? I know a lot of people who insist on doing this even if they just
flew the day before.<BR><BR>Sent from my average intelligence
phone<BR><BR><BR>On May 8, 2013, at 1:44 PM, "Scott McHarg" <<A
href="mailto:scmcharg@gmail.com">scmcharg@gmail.com</A><mailto:<A
href="mailto:scmcharg@gmail.com">scmcharg@gmail.com</A>>>
wrote:<BR><BR>I haven't seen any issues with a battery left a full charge
for a week but I wouldn't recommend longer at full charge. Just make
sure that you DO NOT top off the charge prior to flying. I have
started doing what Keith does as well which eliminates all concerns.
The worst part is having to wait at the field while you bring that battery
back up to 50%. Last one out has to lock the gates.<BR><BR><BR>On Wed,
May 8, 2013 at 11:23 AM, Keith Hoard <<A
href="mailto:klhoard@hotmail.com">klhoard@hotmail.com</A><mailto:<A
href="mailto:klhoard@hotmail.com">klhoard@hotmail.com</A>>>
wrote:<BR>I take my batts to the field at 50% and leave the field at 50%
charge. If I can't do that, then I discharge when I get home. My batts seem
to last a long time.<BR><BR>The (dis)charger is supposed to get hot, that is
where the energy from the battery is going - into the heat sink. That's Ok,
my PL 8 gets hot too.<BR><BR>The PL8 can only discharge 100 watts by itself,
but can do much higher if it is using "regenerative" discharge - dumping
your LiPo's charge back into a lead acid battery. I don't know if the 10X
has that capability or not. Otherwise I'd just keep using the low
discharge rate, or plan your flying day to end with a storage
charge.<BR><BR>Wow, that was a lot of typing to do on a phone!!<BR><BR>Sent
from my iPhone<BR><BR>On May 8, 2013, at 11:15, "Bob Kane" <<A
href="mailto:getterflash@yahoo.com">getterflash@yahoo.com</A><mailto:<A
href="mailto:getterflash@yahoo.com">getterflash@yahoo.com</A>>>
wrote:<BR><BR>I have had to abort a couple of planned flying sessions so far
this spring due to weather. I have read that lipos should not be left
at full charge for any significant length of time. So what is a significant
length of time?<BR><BR>Hours? Days? Weeks?<BR><BR>My Turnigy 10XS
charger has a discharge/storage mode, but the maximum discharge current is 1
amp. It takes a couple of hours to bring a 10S pack down to storage level,
and the charger gets pretty warm(!) during the discharge. Up to now I
have only worried about discharging the pack for long term
storage.<BR><BR>If leaving the cells fully charged for more than a day or so
is bad, I am considering building a dedicated discharger, there are some
pretty simple yet effective designs on RCU.<BR><BR>Bob Kane<BR><A
href="mailto:getterflash@yahoo.com">getterflash@yahoo.com</A><mailto:<A
href="mailto:getterflash@yahoo.com">getterflash@yahoo.com</A>><BR>_______________________________________________<BR>NSRCA-discussion
mailing list<BR><A
href="mailto:NSRCA-discussion@lists.nsrca.org">NSRCA-discussion@lists.nsrca.org</A><mailto:<A
href="mailto:NSRCA-discussion@lists.nsrca.org">NSRCA-discussion@lists.nsrca.org</A>><BR><A
href="http://lists.nsrca.org/mailman/listinfo/nsrca-discussion"
target=_blank>http://lists.nsrca.org/mailman/listinfo/nsrca-discussion</A><BR><BR>_______________________________________________<BR>NSRCA-discussion
mailing list<BR><A
href="mailto:NSRCA-discussion@lists.nsrca.org">NSRCA-discussion@lists.nsrca.org</A><mailto:<A
href="mailto:NSRCA-discussion@lists.nsrca.org">NSRCA-discussion@lists.nsrca.org</A>><BR><A
href="http://lists.nsrca.org/mailman/listinfo/nsrca-discussion"
target=_blank>http://lists.nsrca.org/mailman/listinfo/nsrca-discussion</A><BR><BR><BR><BR>--<BR>Scott
A. McHarg<BR>Sr. Systems Engineer -
Infrastructure<BR>_______________________________________________<BR>NSRCA-discussion
mailing list<BR><A
href="mailto:NSRCA-discussion@lists.nsrca.org">NSRCA-discussion@lists.nsrca.org</A><mailto:<A
href="mailto:NSRCA-discussion@lists.nsrca.org">NSRCA-discussion@lists.nsrca.org</A>><BR><A
href="http://lists.nsrca.org/mailman/listinfo/nsrca-discussion"
target=_blank>http://lists.nsrca.org/mailman/listinfo/nsrca-discussion</A><BR>_______________________________________________<BR>NSRCA-discussion
mailing list<BR><A
href="mailto:NSRCA-discussion@lists.nsrca.org">NSRCA-discussion@lists.nsrca.org</A><BR><A
href="http://lists.nsrca.org/mailman/listinfo/nsrca-discussion"
target=_blank>http://lists.nsrca.org/mailman/listinfo/nsrca-discussion</A><o:p></o:p></P></DIV>
<P class=MsoNormal><BR><BR clear=all><o:p></o:p></P>
<DIV>
<P class=MsoNormal><o:p></o:p> </P></DIV>
<P class=MsoNormal>-- <BR><B><SPAN
style="FONT-SIZE: 13.5pt; FONT-FAMILY: 'Comic Sans MS'; COLOR: #3333ff">Scott
A. McHarg</SPAN></B><BR>Sr. Systems Engineer -
Infrastructure<o:p></o:p></P></DIV></DIV></DIV></BLOCKQUOTE>
<BLOCKQUOTE type="cite">
<DIV><SPAN>_______________________________________________</SPAN><BR><SPAN>NSRCA-discussion
mailing list</SPAN><BR><SPAN><A
href="mailto:NSRCA-discussion@lists.nsrca.org">NSRCA-discussion@lists.nsrca.org</A></SPAN><BR><SPAN><A
href="http://lists.nsrca.org/mailman/listinfo/nsrca-discussion">http://lists.nsrca.org/mailman/listinfo/nsrca-discussion</A></SPAN></DIV></BLOCKQUOTE></DIV>_______________________________________________<BR>NSRCA-discussion
mailing list<BR><A
href="mailto:NSRCA-discussion@lists.nsrca.org">NSRCA-discussion@lists.nsrca.org</A><BR>http://lists.nsrca.org/mailman/listinfo/nsrca-discussion</BLOCKQUOTE></DIV>
<DIV> </DIV></DIV>
<P>
<HR>
_______________________________________________<BR>NSRCA-discussion mailing
list<BR>NSRCA-discussion@lists.nsrca.org<BR>http://lists.nsrca.org/mailman/listinfo/nsrca-discussion</DIV></DIV></DIV></BODY></HTML>