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#1
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posted to rec.boats.cruising
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Sounds like I got something wrong. Please explain.
As I understand it, metal physically moves from the plates into solution as the batteries discharge and back as they charge. Since it doesn't redeposit perfectly, the plates become lumpy. The greater the discharge, the greater this effect. Lower clearance between the plates make the battery less tolerant. Batteries are far from the center of my expertise so I'm not embarrassed to be wrong. What am I missing here? -- Roger Long "Larry" wrote in message ... "Roger Long" wrote in news:wRbEf.1929$5Q3.852 @twister.nyroc.rr.com: deep charging cycles more likely to cause plates to touch. I can tell this is gonna be a LONG thread....(c; |
#2
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posted to rec.boats.cruising
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"Roger Long" wrote in news:ZTlEf.6124$bU6.389
@twister.nyroc.rr.com: As I understand it, metal physically moves from the plates into solution as the batteries discharge and back as they charge. Since it doesn't redeposit perfectly, the plates become lumpy. The greater the discharge, the greater this effect. Lower clearance between the plates make the battery less tolerant. The plates never move...er, ah...we hope! They certainly don't want to touch each other or the battery EXPLODES, almost instantly. Lead acid batteries are very dangerous beasts. Boiling acid from the immense current passing through the acid, turns to steam very quickly and just blows the case apart, spreading acid steam throughout the boat and corroding even the spoons inside the drawers in the galley. Seen that. The chemistry isn't rocket science. The soft lead is eaten away and converted into lead sulphate, in solution we hope in the electrolyte. These ions are fairly stable in the electrolyte so we can recover them later during charging. The conversion releases an amazing amount of electrons at a little over 2V potential very quickly, making it a great starting battery where we need lots of current for a short time. By applying an external potential force, the charger, we can reverse this chemical reaction, electrically, and recover most, but not all, of the ions. Some ions attached themselves to each other forming a crystal of lead sulphate which is VERY stable and, now a solid, falls out of the electrolyte into a special cavity under the plates, out of the way. In AGM batteries, this isn't possible, so I suppose tiny areas of the huge surface area of the wrapped up plates simply become inert. The plates are held apart, because lead is so soft, by insulating separators that are a grid of several materials acid doesn't attack. This holds the plates firmly for moving vehicles. AGM batteries are held in place by the guaze, which performs the same exact function...allow the acid soaked up in the gauze to attack the plates, while holding the plates apart to prevent shorting. AGM isn't as magic as its marketing hype. It's still a 50-year-old lead-acid battery manufactured in a different way to reduce maintenance and volume and production costs. Batteries are far from the center of my expertise so I'm not embarrassed to be wrong. What am I missing here? Don't be embarrassed at all, Roger. The combined knowledge of hulls of everyone else on this forum is probably less than 5% of your knowledge of the subject. We all have our specialties in modern society. You make the hulls more efficient and faster and let us argue over the batteries...(c; This argument over ancient battery technology will soon be moot. Toshiba has used nanotube technology to invent a new Lithium-Ion battery that charges from dead to 80% of its capacity in SIXTY SECONDS and a full 100% charge in less than 3 minutes....while amazingly losing less than 1% of its original capacity (AH rating) in 1000 charge-discharge cycles. This technology may make hybrid and electric cars a reality in our lifetimes. We've never been able to charge any battery fast enough. This battery has solved the problem. You press on the dynamic braking pedal and the big traction motors driving the wheels charge the hell out of the new batteries in the trunk, recovering most of the energy wasted in brake pads on your car so we can use it again and again to drive the car. Electric cars will plug into huge conductors at charging stations to charge at hundreds of amperes while you're inside buying a drink and paying the attendant for the power....in less than 3 minutes. Instead of running the diesel for hours to recharge the house batteries from 1% of its wasted power just waiting for lead and acid to replate the lead plates, the new battery will charge at the full output hp the diesel can produce, the new battery now waiting for the engine, not the other way around. Diesel-electric propulsion will also use the prop's traction motors as generators to recharge the batteries with every available hp under sail.... http://www.physorg.com/news3539.html http://freeenergynews.com/Directory/Battery/index.html MIT is working on a nanotube supercapacitor to store energy instantly. They think possibilities of 100kW/kg is possible, three times what the batteries can store in the same load! Here's the link: http://lees.mit.edu/lees/projects/cn...ap_project.htm Its life will be over 300,000 cycles....never needing replacement?? A better pdf is from the website: http://lees.mit.edu/lees/posters/RU13_signorelli.pdf This nanotube capacitor isn't chemical AT ALL...No chemical reaction takes place....purely electrical in nature, storing the charging electrons over a massive nanotube surface area in a very tiny space. Fuji and Mitsubishi are already in full research: http://www.worldchanging.com/archives/003339.html You plug it in for 5 minutes, it runs 75 miles at 50. They're working to expand this to 124 miles, soon. All in 5 minutes charging....at great power. |
#3
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posted to rec.boats.cruising
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On Thu, 02 Feb 2006 09:40:26 -0500, Larry wrote:
"Roger Long" wrote in news:ZTlEf.6124$bU6.389 : Instead of running the diesel for hours to recharge the house batteries from 1% of its wasted power just waiting for lead and acid to replate the lead plates, the new battery will charge at the full output hp the diesel can produce, the new battery now waiting for the engine, not the other way around. Diesel-electric propulsion will also use the prop's traction motors as generators to recharge the batteries with every available hp under sail.... Now you're talking! A genset and a modded Solomon, with these nanotube babies instead of 14 house batteries and another ton of lead and acid to haul around. Larry, do you know if all that microscopic surface area equals a high mass and/or density? Not that it's likely to be an issue: if these lithium/nanotube batteries have the same weight and dimensions as lead-acid, the ability to rapidly charge alone would find them a ready market. R. |
#4
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posted to rec.boats.cruising
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If you think Rolls and Surette are expensive, just think what 1,000 AH of
lithium-ion batteries is going to cost! :-) -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com "rhys" wrote in message ... On Thu, 02 Feb 2006 09:40:26 -0500, Larry wrote: "Roger Long" wrote in news:ZTlEf.6124$bU6.389 : Instead of running the diesel for hours to recharge the house batteries from 1% of its wasted power just waiting for lead and acid to replate the lead plates, the new battery will charge at the full output hp the diesel can produce, the new battery now waiting for the engine, not the other way around. Diesel-electric propulsion will also use the prop's traction motors as generators to recharge the batteries with every available hp under sail.... Now you're talking! A genset and a modded Solomon, with these nanotube babies instead of 14 house batteries and another ton of lead and acid to haul around. Larry, do you know if all that microscopic surface area equals a high mass and/or density? Not that it's likely to be an issue: if these lithium/nanotube batteries have the same weight and dimensions as lead-acid, the ability to rapidly charge alone would find them a ready market. R. |
#5
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posted to rec.boats.cruising
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On Thu, 02 Feb 2006 15:41:33 -0500, Glenn Ashmore wrote:
If you think Rolls and Surette are expensive, just think what 1,000 AH of lithium-ion batteries is going to cost! :-) This is the problem, and why they won't be used as traction batteries in mass market vehicles for awhile. There's been a lot of talk in battery circles lately about "the lithium economy." Matt O. |
#6
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posted to rec.boats.cruising
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In article 88uEf.17113$Dh.5770@dukeread04,
"Glenn Ashmore" wrote: If you think Rolls and Surette are expensive, just think what 1,000 AH of lithium-ion batteries is going to cost! :-) -- Glenn Ashmore Ahhhhh, but what a Battery you would have, comapred to what is available now...... Bruce in alaska -- add a 2 before @ |
#7
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posted to rec.boats.cruising
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rhys wrote in news:epl4u1tijpucflmocbnuf3a5ib100bhlue@
4ax.com: Larry, do you know if all that microscopic surface area equals a high mass and/or density? Not that it's likely to be an issue: if these lithium/nanotube batteries have the same weight and dimensions as lead-acid, the ability to rapidly charge alone would find them a ready market. R. They are TINY by comparison. That little Li-Ion cell in the picture with the big spade lugs coming out the bottom is something like 5AH! The name of all this game is SURFACE AREA. The tiny tubes have a larger surface area than any known thing on the planet! Microscopic channels where electrons can be stored, directly, like in the ultracapacitor or chemically in Lithium ions....all in parallel for amazing capacity. Keep a close eye on this evolving technology. At the moment, it answers a LOT of tough questions about electron storage we never had answers for, before. Tiny and light....a cellphone you charge once a month in 3 minutes flat. Next time that damned VHF marine handi goes dead 500 yards from the dockhand you're trying to talk to, wish those cheap-assed NiCds NMEA put in it were these new Li-Ion cells....(c; |
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