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<DIV><FONT face=Arial size=2>I don't think that there is any value or advantage
in cycling down an NiMH pack because they do not display any memory behavior.
(Like a Nicad)</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=Arial size=2>On the other hand I guess you/we will always need
to know how much a battery has left in it.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I was told that you should not take an NiMH battery
down too low. I have killed a few of them by leaving them on too long and once
flew too many times and was lucky to get the plane down with one servo action at
a time. The pack would not charge back up!</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I am curious as to what charger/cycler you are
using. How many cells and what voltage you show after charging and then with a
500 ma load?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Regards,</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Eric.</FONT></DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>----- Original Message ----- </DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=precisionaero@comcast.net
href="mailto:precisionaero@comcast.net">Michael Cohen</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Thursday, February 23, 2006 9:48
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [NSRCA-discussion] NiMH
Question</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>I am cycling my batteries and getting ready for
the flying season. On my initial 5 cycle run at my NiMH batteries, both
my 1650 mAh packs cycled very low. One pack that I have not used since
end of November only cycled up to 850 mAh and the other pack I have not used
since end of September only cycled up to 1000 mAh. My charger is set to
5 cycles, charge and discharge are set to .65 amps with a cutoff voltage at
1.1 Volts per cell. I am now trying 1.00 amp charge/discharge with a 1.0
volt per cell cutoff and it is looking better, but I have some
questions:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>1) Did I damage the batteries by letting
them self-discharge too low? I know NiMH batteries have a higher self
discharge rate than NiCD batteries, but I am not aware letting the NiMH
batteries run down could cause damage.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>2) Is this a normal behavior? Maybe
NiMH just need a little more juice at the beginning of the
season.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>3) Is the cold garage a
factor?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Thoughts?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Mike Cohen</FONT></DIV>
<P>
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