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Yeah again,
<br>That Troy always gives me the nitty-gritty details that I can't get
anywhere else!!!
<br>You're fantastic Troy. I couldn't make it without ya. Thanks for the
full scoop!
<br>G.
<p>T&C Brown wrote:
<blockquote TYPE=CITE><style></style>
<font size=-1>Yeah......What Troy
said.... :-)</font><font size=-1>T-Bone</font>
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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 href="mailto:troy_newman@msn.com" title="troy_newman@msn.com">Troy Newman</a></div>
<div style="FONT: 10pt arial"><b>To:</b> <a href="mailto:discussion@nsrca.org" title="discussion@nsrca.org">discussion@nsrca.org</a></div>
<div style="FONT: 10pt arial"><b>Sent:</b> Sunday, August 31, 2003 5:48
PM</div>
<div style="FONT: 10pt arial"><b>Subject:</b> Re: Lithium or Not ?</div>
<font face="Arial"><font size=-1>Li-ion packs.</font></font> <font face="Arial"><font size=-1>Bob,
and Lance.....</font></font><font face="Arial"><font size=-1>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></font> <font face="Arial"><font size=-1>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></font> <font face="Arial"><font size=-1>Let
me repeat the Lithium-ion packs are not the same packs as caused that guys
fire.</font></font> <font face="Arial"><font size=-1>OK</font></font> <font face="Arial"><font size=-1>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></font> <font face="Arial"><font size=-1>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></font> <font face="Arial"><font size=-1>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></font> <font face="Arial"><font size=-1>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></font> <font face="Arial"><font size=-1>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></font> <font face="Arial"><font size=-1>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></font> <font face="Arial"><font size=-1>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></font> <font face="Arial"><font size=-1>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></font> <font face="Arial"><font size=-1>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></font> <font face="Arial"><font size=-1>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></font><font face="Arial"><font size=-1>And
not priced too much out of range.....$35 a pack....this is slightly higher
than a 2000mah Nicd pack...</font></font> <font face="Arial"><font size=-1>Troy</font></font></blockquote>
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