"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.