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#1
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![]() 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 |
#2
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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 |
#3
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![]() 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 |
#4
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![]() 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? |
#5
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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 |
#7
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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 |
#8
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On 31 Aug 2003 00:16:41 -0700, wrote:
Badwater may be a physicist but he's not too bright. I just received 2 Panasonic 20 AH RG batteries from Digikey. They were about $42 each. They are about 2.99 wide, 7.13" long, and 6.58" high, weigh 14.34 lbs each. Same chemistry and internal physical construction as the Odyssey. ++++++++++++++++++++++++++++++++++++++++++ What a meanie you are. 8-D I was made aware of these Panasonics some time ago through the RV list..... but, who am I to bust anyone's bubble? g Barnyard BOb -- bargain hunter |
#9
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![]() Rob Cherney wrote: 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. I use a sealed lead-acid lawn tractor battery from the local automobile parts store in my Long EZ -- about $25 as I recall. I swap it out every 2 to 3 years. It cranks in 20 degree F temps and I've never had one fail. I prefer this to buying an expensive battery and hoping it will last 4+ years. Too heavy? Not for me. In fact I have two 8 lb lead shot bags straddling the thing. David O -- http://www.AirplaneZone.com |
#10
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![]() Barnyard BOb -- wrote: On 31 Aug 2003 00:16:41 -0700, wrote: Badwater may be a physicist but he's not too bright. I just received 2 Panasonic 20 AH RG batteries from Digikey. They were about $42 each. They are about 2.99 wide, 7.13" long, and 6.58" high, weigh 14.34 lbs each. Same chemistry and internal physical construction as the Odyssey. ++++++++++++++++++++++++++++++++++++++++++ What a meanie you are. 8-D I was made aware of these Panasonics some time ago through the RV list..... but, who am I to bust anyone's bubble? g Barnyard BOb -- bargain hunter I was aware of that battery also Bob but the other guy posting here does not have a clue what he is talking about. They ARE NOT the same battery. The Odyssey is a dry cell battery and the Panasonic is a lead acid battery. For the purpose that BWB is using his the Panasonic would never stand up to the charge/discharge he is doing. I did a lot of research before buying the Odyssey battery. I Also looked at the LC-X1220 from Digikey. Not bursting any bubbles here maybe if would do some more research his bubble may burst. The guys using the Panasonic in their RVs are finding that the cranking power gets weaker rapidly while the Odyssey keeps right on ticken. I have the spec sheets for both batteries. Jerry |
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