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<DIV><SPAN class=466301020-04092003><FONT face=Arial color=#0000ff size=2>I
would add that we get focussed on the battery and not the charger. All batteries
will do something nasty if seriously overcharged.</FONT></SPAN></DIV>
<DIV><SPAN class=466301020-04092003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=466301020-04092003><FONT face=Arial color=#0000ff size=2>I pay
a lot of attention to what Jim O. tells me. If the charger will not prevent an
overcharge then you have high risk situation. Jim has written about this
before.</FONT></SPAN></DIV>
<DIV><SPAN class=466301020-04092003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=466301020-04092003><FONT face=Arial color=#0000ff
size=2>Regards,</FONT></SPAN></DIV>
<DIV><SPAN class=466301020-04092003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=466301020-04092003><FONT face=Arial color=#0000ff
size=2>Eric.</FONT></SPAN></DIV>
<DIV><SPAN class=466301020-04092003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=466301020-04092003><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<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>Troy
Newman<BR><B>Sent:</B> Sunday, August 31, 2003 6:49 PM<BR><B>To:</B>
discussion@nsrca.org<BR><B>Subject:</B> Re: Lithium or Not
?<BR><BR></FONT></DIV>
<DIV><FONT face=Arial size=2>Li-ion packs.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Bob, and Lance.....</FONT></DIV>
<DIV><FONT face=Arial size=2>I have been running these 2000mah packs since
February. They are a 2 cell pack. Central sells them for $35 a pack and they
have a $50 charger....Here is the kicker. The charger is plug in and forget. It
can't harm the batteries even if left on charge for 3 months. Its basically a
voltage regulator setup where it puts out 8.4V and when the pack reaches 8.4V
its done....The nice thing is the charger has a Amp meter on it so when the
battery is empty it might take 1-1.3amps but as it charges the current flow goes
to zero. Once the pack is charged up the current flow is zero and no juice is
going to the battery. You're not waiting for a light to turn color or go
out...You can see what is actually going into the battery.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Lance the pictures of the plane that burned up were
a guy using Lithium Metal cells. These were the first Duralite batteries....The
industry folks got away from Li-Metal as it was highly highly dangerous when the
electrolyte came in contact with the air....and would burn....</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Let me repeat the Lithium-ion packs are not the
same packs as caused that guys fire.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>OK</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Here is the scoop on what I use. 1 battery pack 2
cells its rated at 2000mah....I can pull about 2200 out of it before it
reaches the magic stop voltage. The pack has a great discharge curve it is
almost linear until the pack is near dead. So every flight might use say 0.15V
per flight....It starts at 8.4V and I stop flying at 7.2V on my Volt meter with
a 500mah load. They say you should use a 1amp load to test the voltage. What I
did was plot a curve of the discharge. I stuck the battery on a cycler for 15min
"flights" pulling the exact same mah out of the pack each "flight" I then
plotted it on a graph vs. time. This gave a sharp knee when the pack is almost
of out power.....What happens is as the packs fall below 7V there is not much
left in them...Even though the cutoff is officially like 6V or 5.5V depending on
the company selling you the battery...By the way many of them are the same
cells. And I have driven the pack down to around 5V and they are still fine. I
tested the batts about 4-5 times and got the exact same response everytime...So
I flew them and got the exact same response as if I was having the pack sit on
the cycler....I use about 180-200ma per flight</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Setup...1 pack 2000mah, 1 Oddino regulator
5.3V...and go...... the setup weights about 3.8-4oz total. I can fly around 8-10
flights in a day and still have enough for more flights but its getting close to
time charge. Charge up is about 2-3hrs on a dead battery pack. The charger
runs on a 12V source so you can "field" charge it just doesn't charge any faster
than the 2-3hrs on a dead pack...However...With the AMP meter on the charger you
can get an idea of the charge level left in the pack. Plug it in and it draws
300ma...then you still about 3/4 of the battery remaining....if it draws around
1amp its almost dead...and needs some time on the charger...If for example its
drawing 1amp and 1 hr later its down to about a 200mah draw on the
charger...pull it off and fly it some more....it will jump into the curve like
it already had 2-3 flights on it....and act the same as it did on flights 4-5-6
from a full charge....There is no memory, no need to drain the pack before
charging....you can charge after one flight or after 10
flights.....</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Also if you charge and don't fly for like a
month...the battery is still sitting at about 98% full charge....I have a pack I
charged before the Team Trials....just measured it and full its 8.4V and it
reads today 8.31V...It was charged last in Mid JUNE! Like the 10th of June...and
its still got 8-9 flights in it....</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>These packs are awesome. They are dummy proof and
allow me to fly all day long...now your mileage may vary depending on your
battery drain....But I'm running a YS DZ on a Hyde Mount with 5 digitals even a
little 3421 on the throttle.....9411SA's on the Ailerons and 8411SA's on rudder
and Elevator...So I'm working the packs pretty hard...</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Just ask ole' man Whitachre...Bob would come out
this spring and what me fly all day on two models...I would drain 2 gallons of
fuel just flying back to back to back...about 16-18 flights in a day....and
never charge...just fuel, test, and fly.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Since being in GA I have been out much less than
before the NATS and I have gone flying 2-3 days on the same charge. Maybe
3-4 flights per day.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I love the way they work.....Can't speak for the
Duralite, Powerflite, and others...but the Central Hobby packs are great....I
gave all my Nicd packs away to guys that will use them. I don know the
Powerflite and the NMP (centrals) are the same cells. As are the
Superbatterypacks.com, and some of the other suppliers...Now Duralite and
Powerflite have special chargers that are expensive but they can charge 2-3-4-5
packs at a time....this charger only does one pack at a time....buts a dummy
proof charger...reverse polarity it doesn't do anything...lites a red LED to
tell its backwards....Green LED says Polarity is good and plu it in....If the
amp meter says zero its charged....If it reads 1.3amps the pack was
dead....pretty simple...and you can use the charger like a fuel meter....the
closer the meter is to zero the more charge is inside the battery
pack....</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>As for the age issue. My packs are pretty new...but
I know people that have packs going on 2 years old now. The age failure seems to
be a slow loss in capacity...as the pack gets old...they simply don't reach 8.4V
any longer...Instead they it 8.2 then 7.9V and then slowly creep down to
7.5V....At this time is when you know to get a new one. </FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I have 2 packs I have flown since Feb....that's
going on 28 cases yes cases of fuel this year.....I'm approaching 1000 flights
just this year flying two different models...I think the technology is pretty
sound and works well. I was leery before as I had some bad luck with the old
style li-METAL packs Duralite originally sold....These packs are much more
forgiving and easier to manage.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>I would recommend them over ni-cds or
Nimh....weight is not so much the issue its the consistent discharge
curve....they are AWESOME.....</FONT></DIV>
<DIV><FONT face=Arial size=2>And not priced too much out of range.....$35 a
pack....this is slightly higher than a 2000mah Nicd pack...</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Troy</FONT></DIV></BODY></HTML>