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<DIV><FONT face=Arial size=2>But what if the BatShare fails? I don't see how
this is advantageous to having two completely independent circuits going into
the RX.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Keith Black</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=d.pappas@kodeos.com href="mailto:d.pappas@kodeos.com">Dean Pappas</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=discussion@nsrca.org
href="mailto:discussion@nsrca.org">discussion@nsrca.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, January 24, 2005 1:11
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> RE: any merit in running dual
battery packs ?</DIV>
<DIV><BR></DIV>
<DIV><SPAN class=746360619-24012005><FONT face=Arial color=#0000ff size=2>Hi
Ron,</FONT></SPAN></DIV>
<DIV><SPAN class=746360619-24012005><FONT face=Arial color=#0000ff
size=2>Nickel tends to fail short. That's actually good. Once upon a time,
Orbit sold its packs with diodes across each cell to protect against
failed-open cells.</FONT></SPAN></DIV>
<DIV><SPAN class=746360619-24012005><FONT face=Arial color=#0000ff
size=2> Try the Smart-Fly BATshare ... same bat time, same bat
channel!</FONT></SPAN></DIV>
<DIV><SPAN class=746360619-24012005><FONT face=Arial color=#0000ff size=2><A
href="http://www.smart-fly.com/Products/BatShare/batshare.htm">http://www.smart-fly.com/Products/BatShare/batshare.htm</A></FONT></SPAN></DIV>
<DIV><SPAN class=746360619-24012005><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=746360619-24012005><FONT face=Arial color=#0000ff
size=2>later,</FONT></SPAN></DIV>
<DIV><SPAN class=746360619-24012005> <FONT face=Arial
color=#0000ff size=2>Dean</FONT></SPAN></DIV>
<P><FONT face="Times New Roman">Dean Pappas</FONT> <BR><FONT
face="Times New Roman">Sr. Design Engineer</FONT> <BR><FONT
face="Times New Roman">Kodeos Communications</FONT> <BR><FONT
face="Times New Roman">111 Corporate Blvd.</FONT> <BR><FONT
face="Times New Roman">South Plainfield, N.J. 07080</FONT> <BR><FONT
face="Times New Roman">(908) 222-7817 phone</FONT> <BR><FONT
face="Times New Roman">(908) 222-2392 fax</FONT> <BR><FONT
face="Times New Roman">d.pappas@kodeos.com</FONT> </P>
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<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B>
discussion-request@nsrca.org [mailto:discussion-request@nsrca.org]<B>On
Behalf Of </B>ronlock@comcast.net<BR><B>Sent:</B> Monday, January 24, 2005
1:40 PM<BR><B>To:</B> discussion@nsrca.org<BR><B>Subject:</B> Re: any merit
in running dual battery packs ?<BR><BR></FONT></DIV>
<DIV>I wanted redundancy in the power system for my pattern birds, but
without ANY new potential points of failure. My confinguration
is:</DIV>
<DIV>Two 700mah 5 cell batt packs. Each pack direct to a
switch, direct to Receiver.</DIV>
<DIV>No regulators, diodes, etc. </DIV>
<DIV>I'm more concerned about connector, switch, and solder
joint failures in the pack, than failure of a battery cell. This
config gives me redundancy in those areas.</DIV>
<DIV>When things go normally, I have 1400mah available with only a slight
weight gain over a single larger pack, switch & wiring.</DIV>
<DIV> </DIV>
<DIV>I understand cells more often fail open, than short. But in
case of a short, (the worst case for this config) the good pack must
fly the plane, and charge the "bad" pack for duration of the
flight. After research & discussion with others, it's my
belief the good pack will tolerate the load of charging the bad one
(which won't be at a very high rate) and finishing a flight. </DIV>
<DIV> </DIV>
<DIV>A potential failure point is me. (darn humans!)
My duties as crew chief include checking both batts before every
flight, and turning on both before flight.</DIV>
<DIV> </DIV>
<DIV>Later, Ron Lockhart</DIV>
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Original message -------------- <BR>
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<DIV>
<DIV>In a message dated 1/24/2005 7:19:07 AM Eastern Standard Time,
hitesh@salt.ac.za writes:</DIV>
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style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" face=Arial color=#000000 size=2>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=095360912-24012005>Hi,</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=095360912-24012005></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=095360912-24012005>Now that we all using high powered digital
servo's with incredible holding power etc - is there any merit in
running 2 battery packs, say 1 Ah each as opposed to 1 high capacity
pack thereby eliminating the single point failure ? If I did want
to run 2 packs, is a diode necessary to prevent 1 pack from possibly
charging the other if 1 pack were to go bad ?</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=095360912-24012005></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=095360912-24012005>Cheers,</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=095360912-24012005>Hitesh</SPAN></FONT></DIV></FONT></BLOCKQUOTE></DIV>
<DIV> </DIV>
<DIV>Hitesh, a 1500 to 2000ma battery is all you need. There's little
advantage to redundancy unless you are planning to fly more than 5-7
flights (res) on any given day. But then again, I use NiMH on the airborne
and only Sanyo packs, which have proven extremely reliable for several
years now. As such, a redundant power source isn't really necessary
in pattern models and you can avoid some unnecessary weight build up.
</DIV>
<DIV> </DIV>
<DIV>What has been done in large models is to add another
battery and switch harness to an unused channel on the receiver,
which provides adequate redundancy. The extra weight on such models isn't
as critical as it is in pattern models. Both switches "on" at take-off
please.</DIV>
<DIV> </DIV>
<DIV>Of course, if you just have to have the extra battery and you have
enough weight margin and room, the above is one way to do it. There are
other ways, but this is simple and reliable.</DIV>
<DIV> </DIV>
<DIV>MattK</DIV></FONT></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>