Odyssey Battery-Jerry Springer

Okay Jerry, I took your advice and spent $135 bucks today for an
Odyssey 16 Amp-hr dry cell that weighs 15 pounds (the 680). I cut the
aluminum for a bracket on the gyroscope to mount it but I gotta get
Kevin to TIG weld it later today.

As far as the battery goes, I hope that MOFO spools me up more than
once and still starts the Rotax 582 to boot. I don't know how much
current I'm pulling on the startup of the main rotor system but I'm
using jumper cable wire and it heats up. I think I'll hand start the
blades a bit first instead of just doing the dead start because the
dead start looks like a dead short for the first few seconds of the
sequence. When I was buying this battery at the store the guys there
told me it was designed for Harley's of all things. They also told me
that a battery that cost's half as much is the Deka Battery. But, the
Deka does have a vent and it's a high pressure vent, where the Odyssey
has none and no acid can leak out.

I've not been to the Deka site to see the specs but I do have a spec
sheet. Nowhere does it say that you can deep discharge this baby like
the Odyssey and recharge it completely--400 times. Jesus...400 deep
cycle recharges on the odyssey and they warrantee it. That's kicking
some tall ass to do that.

Another goofy thing about the Odyssey is that you can't recharge it
using a trickle charger. Less than 1.25 Amps won't put all the energy
back into the battery. You have to use a 10 Amp charger to get back
to full energy. Anybody know the chemistry behind that? I don't get
it. Lead peroxide is lead peroxide. When you drive the sulfate off
the lead atom and reattach an oxygen, what the hell difference does it
make how fast you do it (high Amps)? The only thing I can think of is
that the battery itself has an internal resistance of 7 Ohms so the
higher the current, the higher the temperature of the battery itself.
And, as you all know, for every 10 degrees Centigrade, the chemical
reactivity rate coefficient doubles. So, the rate constant will be
higher for the charge cycle on a hot battery. They say you can
completely recharge this baby in 2 hours if you use 10 Amps. I'm
thinking that it heats up...that's why!

Badwater "I got me a new stinking battery" Bill

Ouch, :-( Sunn battery has them for $74.00+ $5.00 shipping. That was in
my first message about the battery. I hope it works for you Bill, really
works great in my RV. Better than any Gell cell, or RG battery I have
ever tried before.
http://sunnbattery.com/item.jhtml?UC...0&PRID=1292858
Jerry

Badwater Bill wrote:
Okay Jerry, I took your advice and spent $135 bucks today for an
Odyssey 16 Amp-hr dry cell that weighs 15 pounds (the 680). I cut the
aluminum for a bracket on the gyroscope to mount it but I gotta get
Kevin to TIG weld it later today.

As far as the battery goes, I hope that MOFO spools me up more than
once and still starts the Rotax 582 to boot. I don't know how much
current I'm pulling on the startup of the main rotor system but I'm
using jumper cable wire and it heats up. I think I'll hand start the
blades a bit first instead of just doing the dead start because the
dead start looks like a dead short for the first few seconds of the
sequence. When I was buying this battery at the store the guys there
told me it was designed for Harley's of all things. They also told me
that a battery that cost's half as much is the Deka Battery. But, the
Deka does have a vent and it's a high pressure vent, where the Odyssey
has none and no acid can leak out.

I've not been to the Deka site to see the specs but I do have a spec
sheet. Nowhere does it say that you can deep discharge this baby like
the Odyssey and recharge it completely--400 times. Jesus...400 deep
cycle recharges on the odyssey and they warrantee it. That's kicking
some tall ass to do that.

Another goofy thing about the Odyssey is that you can't recharge it
using a trickle charger. Less than 1.25 Amps won't put all the energy
back into the battery. You have to use a 10 Amp charger to get back
to full energy. Anybody know the chemistry behind that? I don't get
it. Lead peroxide is lead peroxide. When you drive the sulfate off
the lead atom and reattach an oxygen, what the hell difference does it
make how fast you do it (high Amps)? The only thing I can think of is
that the battery itself has an internal resistance of 7 Ohms so the
higher the current, the higher the temperature of the battery itself.
And, as you all know, for every 10 degrees Centigrade, the chemical
reactivity rate coefficient doubles. So, the rate constant will be
higher for the charge cycle on a hot battery. They say you can
completely recharge this baby in 2 hours if you use 10 Amps. I'm
thinking that it heats up...that's why!

Badwater "I got me a new stinking battery" Bill

On Sun, 31 Aug 2003 00:24:41 GMT, Jerry Springer
wrote:

Ouch, :-( Sunn battery has them for $74.00+ $5.00 shipping. That was in
my first message about the battery. I hope it works for you Bill, really
works great in my RV. Better than any Gell cell, or RG battery I have
ever tried before.
http://sunnbattery.com/item.jhtml?UC...0&PRID=1292858
Jerry


Hell, that was after calling all the retailers on the page at the
Odysey website. It was $126 plus tax. Most wanted nearly $140.
Something is wrong somewhere.

Bill

Okay Jerry, I took your advice and spent $135 bucks today for an
Odyssey 16 Amp-hr dry cell that weighs 15 pounds (the 680). I cut the
aluminum for a bracket on the gyroscope to mount it but I gotta get
Kevin to TIG weld it later today.

Badwater "I got me a new stinking battery" Bill
+++++++++++++++++++++++++++++++++++++++++

I ain't no genius, but my thoughts are that....
the Odyssey battery is all wrong for your application.

Now go ahead and make a fool of me. g


Barnyard BOb -- needing of a large charge

Barnyard BOb -- wrote:

Okay Jerry, I took your advice and spent $135 bucks today for an
Odyssey 16 Amp-hr dry cell that weighs 15 pounds (the 680). I cut the
aluminum for a bracket on the gyroscope to mount it but I gotta get
Kevin to TIG weld it later today.


Badwater "I got me a new stinking battery" Bill

+++++++++++++++++++++++++++++++++++++++++

I ain't no genius, but my thoughts are that....
the Odyssey battery is all wrong for your application.

Now go ahead and make a fool of me. g


Barnyard BOb -- needing of a large charge

If he is using a battery which one would work better Bob?

On Sun, 31 Aug 2003 00:41:14 GMT, Jerry Springer
wrote:



Barnyard BOb -- wrote:

Okay Jerry, I took your advice and spent $135 bucks today for an
Odyssey 16 Amp-hr dry cell that weighs 15 pounds (the 680). I cut the
aluminum for a bracket on the gyroscope to mount it but I gotta get
Kevin to TIG weld it later today.


Badwater "I got me a new stinking battery" Bill

+++++++++++++++++++++++++++++++++++++++++

I ain't no genius, but my thoughts are that....
the Odyssey battery is all wrong for your application.

Now go ahead and make a fool of me. g


Barnyard BOb -- needing of a large charge

If he is using a battery which one would work better Bob?
+++++++++++++++++++++++++++++++++++

How about a_40 lb_Odyssey, Jerry? g

The first concern is to successfully SIZE the battery
to this unique demanding application. A 16 amp-hour
Odyssey is going to empty out pretty quick unless one
is willing to start the blades rotating by hand. If one has
to do that, one may decide that the starter, battery, etc are
not worth all the time, effort, weight, complexity and cost.

OTOH......
just keep upsizing the battery until satisfactory performance
is achieved or the gyro is too heavy to fly. g

All this is going through my mind without a shred of
practical experience. So.... take it for what it's worth.


Barnyard BOb -- thinking out loud

Barnyard BOb -- wrote in message . ..
.... A 16 amp-hour
Odyssey is going to empty out pretty quick unless one
is willing to start the blades rotating by hand. ....

I am using the PC680 Odyssey battery for starting
a 10.5/1, 220HP Franklin engine. It has no trouble
cranking the thing. True, at 225amps cranking the
battery won't last more than a few minutes. But if
the thing does not start in the first 5-10 seconds,
there is something else wrong.

----------------------------------------------------
Paul Lee, SQ2000 canard project: www.abri.com/sq2000

On 3 Sep 2003 14:12:04 -0700, (Paul Lee) wrote:

Barnyard BOb -- wrote in message . ..
.... A 16 amp-hour
Odyssey is going to empty out pretty quick unless one
is willing to start the blades rotating by hand. ....

I am using the PC680 Odyssey battery for starting
a 10.5/1, 220HP Franklin engine. It has no trouble
cranking the thing. True, at 225amps cranking the
battery won't last more than a few minutes. But if
the thing does not start in the first 5-10 seconds,
there is something else wrong.

That's an interesting application. The 680 is only 15 pounds and it's
small in volume, that's why I like it. I got a hold of a couple 35
Amp-hr Gel Cell batteries today from a buddy (brand new out of the box
and he just gave them to me since his application disappeared). I'm
going to make an APU out of them and use them to hook up in parallel
during my starts. That way I'll have plenty for the flying day.

My real problem here, and I haven't talked about it, is that my blades
aren't tracked properly. I've painted one tip red and one black. You
can't track them without flying the damn thing. In flight, you look
at the tips and see what blade is above the other. Then you land and
reduce AOA on the high blade, spool up again and go for another try.
It's an empirical thing until you get it dialed in. The problem with
a Walmart motorcycle battery is that I get about three starts from it
with a 30 minute charging time between each start and the battery is
toast since it deep cycles to full discharge. That battery is simply
not designed for what I need to do.

Another problem is that I have to crank the engine after I start the
main rotor blades and get them into autorotation facing into the wind.
If there is no wind, I have to taxi to make relative wind and I have
to start the Rotax 582 to do that. I can't do that without a Mambo
battery.

BWB

On Sat, 30 Aug 2003 23:32:20 GMT, (Badwater
Bill) wrote:

Another goofy thing about the Odyssey is that you can't recharge it
using a trickle charger. Less than 1.25 Amps won't put all the energy
back into the battery. You have to use a 10 Amp charger to get back
to full energy.

From their data, it looks like the charge efficiency sharply decreases
below 0.1C (1C = rated A-h @ 10h discharge rate). This is 1.6A for
your battery. Note that this only applies to a fully discharged
battery.

Anybody know the chemistry behind that? I don't get
it. Lead peroxide is lead peroxide. When you drive the sulfate off
the lead atom and reattach an oxygen, what the hell difference does it
make how fast you do it (high Amps)?

Hawker doesn't say specifically, but reading between the lines it
looks like it could be a function of the small amount of tin that's
added to the lead in the plates. This is done to increase service
life for deep-discharge applications. Don't ask me about tin
chemistry, though. I'm an electronics weenie.

The only thing I can think of is
that the battery itself has an internal resistance of 7 Ohms so the
higher the current, the higher the temperature of the battery itself.
And, as you all know, for every 10 degrees Centigrade, the chemical
reactivity rate coefficient doubles.

Two things:

The internal resistance is 7 milliohms.

The primary aging mechanism for these batteries is corrosion of the
positive electrode grid. For this particular mechanism, the reaction
doubles every 8 °C, not 10° C as one would expect.

So, the rate constant will be
higher for the charge cycle on a hot battery. They say you can
completely recharge this baby in 2 hours if you use 10 Amps. I'm
thinking that it heats up...that's why!

Yep, and that's not unique to this particular battery.

Actually, Odyssey says the battery can be recharged in as little as 20
minutes, assuming you have a charger that's beefy enough (3.5C= 56 A).
At this rate, the internal temperature will rise about 20 °C and will
peak about the time charging current starts decreasing (assumes the
recommended voltage-limited constant-current charging).

For a 2-hour charge, the expected temperature rise will be only about
10 °C.

By the way, my information came from http://www.hepi.com/papers.htm.
I pretty sure the Odyssey battery is an evolution of the Cyclon and
Genesis batteries that are mentioned in the papers.

Lastly...

I did a lot of research on batteries and settled on the Odyssey when a
replacement was needed for Long-EZ N271J. I put a PC-925 (27 A-h) in
her back in February. So far, so good.


Rob-
------------------------------------------------------------------
Robert Cherney e-mail: rcherney(at)comcast(dot)net

I've been running an Odyssey PC 625 battery cranking my 0320 Lycoming for
several years. Cranke the think at 20 degrees in Canada. The only problem
was that I had to add some lead wts in the battery box to keep the c.g.
where it was.
Stu Fields
"Rob Cherney" wrote in message
...
On Sat, 30 Aug 2003 23:32:20 GMT, (Badwater
Bill) wrote:

Another goofy thing about the Odyssey is that you can't recharge it
using a trickle charger. Less than 1.25 Amps won't put all the energy
back into the battery. You have to use a 10 Amp charger to get back
to full energy.

From their data, it looks like the charge efficiency sharply decreases
below 0.1C (1C = rated A-h @ 10h discharge rate). This is 1.6A for
your battery. Note that this only applies to a fully discharged
battery.

Anybody know the chemistry behind that? I don't get
it. Lead peroxide is lead peroxide. When you drive the sulfate off
the lead atom and reattach an oxygen, what the hell difference does it
make how fast you do it (high Amps)?

Hawker doesn't say specifically, but reading between the lines it
looks like it could be a function of the small amount of tin that's
added to the lead in the plates. This is done to increase service
life for deep-discharge applications. Don't ask me about tin
chemistry, though. I'm an electronics weenie.

The only thing I can think of is
that the battery itself has an internal resistance of 7 Ohms so the
higher the current, the higher the temperature of the battery itself.
And, as you all know, for every 10 degrees Centigrade, the chemical
reactivity rate coefficient doubles.

Two things:

The internal resistance is 7 milliohms.

The primary aging mechanism for these batteries is corrosion of the
positive electrode grid. For this particular mechanism, the reaction
doubles every 8 °C, not 10° C as one would expect.

So, the rate constant will be
higher for the charge cycle on a hot battery. They say you can
completely recharge this baby in 2 hours if you use 10 Amps. I'm
thinking that it heats up...that's why!

Yep, and that's not unique to this particular battery.

Actually, Odyssey says the battery can be recharged in as little as 20
minutes, assuming you have a charger that's beefy enough (3.5C= 56 A).
At this rate, the internal temperature will rise about 20 °C and will
peak about the time charging current starts decreasing (assumes the
recommended voltage-limited constant-current charging).

For a 2-hour charge, the expected temperature rise will be only about
10 °C.

By the way, my information came from http://www.hepi.com/papers.htm.
I pretty sure the Odyssey battery is an evolution of the Cyclon and
Genesis batteries that are mentioned in the papers.

Lastly...

I did a lot of research on batteries and settled on the Odyssey when a
replacement was needed for Long-EZ N271J. I put a PC-925 (27 A-h) in
her back in February. So far, so good.


Rob-
------------------------------------------------------------------
Robert Cherney e-mail: rcherney(at)comcast(dot)net