New Magnesium Rechargable Battery

[trailstoride]

Check out this Made from magnesium, it is light, non-toxic and cheap. The technology might eventually replace lead-acid and nickel-cadmium packs for powering vehicles and storing electricity.

And this The new battery can be recharged over 2,000 times and produces up to 1.3 volts -- similar to comparable existing systems. Aurbach says that it should be commercially available within a year


Looks promising!

 

[Floating Spots]

Is there a method where the metal could ignite?
Like under a short circuit?
Or a car fire?
I wonder if you have to carry your own Purple K fire extinguisher?
What would the fire departments do (without water).

There is no (specific) talk about the energy/volume or energy/weight.
I wonder how it will stack up.

 

[FreeBSDboy]

Fire departments also cary foam.

That and they're not using a pure magnesium, they're using some form of magnesium alloy. But I have no idea how that affects it's ability to ignite.

You'd probably also have to have all the electrolyte drained out of the battery somehow. Or have it boiled off in a fire, but by that point you'd have the larger problem of being dead and I really don't think you'd care too much if the magnesium in the battery ignited.

 

[MrAl]

Hello,

Sounds very good, i cant wait to see some myself.

Al

 

[James S]

Not to pull this too far off topic /ubbthreads/images/graemlins/wink.gif But I seem to have a memory of a method of fighting larger scale metal fires that involved spraying a chemical on them that put it out by absorbing and carrying away so much heat that it would not be able to continue burning.

Is that what is in a "purple-k" fire extinguisher? Is there such a thing and what is it?

to keep it on topic, various magnesium alloys have been used in laptop computer cases and all sorts of uses and they are not nearly as flammable as straight magnesium. So it's very possible that the alloying would render it mostly harmless...

 

[FreeBSDboy]

I think Purple K fire extinguishers are dry chemical extinguisher that is used primarily for oil / gas / greese fires. They were developed for commercial cooking applications where regular class B fire extinguishers were having trouble

Metal fires need a class D combustible metals extinguisher.

 

[Floating Spots]

Purple K is the what the chemical in a class D fire extinguisher is.
It covers exotic metal fires and melts to a glasslike cover. It thus keeps the oxygen out of the metals. It traps the heat, though, so if it is disturbed before the metal below cools (many hours) a reignition may/will occur.

Magnesium and other exotic metals don't like to start in block or some highly alloyed forms. However, this alloy is fairly pure. The other thing it has going for/or against you is that the battery plates are thin and thus very conducive to ignition.

Will foam work on exotic metals?
I thought it was as bad as water on these fires.

I shouldn't have jumped on this like that.
I'm sure it will be properly tested before making it to market.

However, I could see problems with crashes, shorted batteries, etc. (especially if it wasn't distructively tested).

 

[FreeBSDboy]

I think problems with crasing of electric cars will be more along the lines of worrying about high current DC electrical wiring. If a firefighter accidently cut through a cable coming from a large battery pack - byebye jaws of life. The end would either be vaporized or perminently welded to the frame... or both. And hopefully your batteries don't explode from being shorted out.

Floating sports: While it may be the same chemical ( I really don't know), my point was there is a difference between class K fire extinguishers and class D fire extinguishers as recognized by the NFPA. Being as I don't really want to pay to read the NFPA 10 standards, I couldn't tell you what they are.

 

[PsycoBob[Q2]]

For the pack DC lines, routing them as far apart as possible, and NEVER grounding the main pack to the frame is a good idea. Usually a fuse/breaker combo is used inside the pack, with another at the controller, plus an impact-sensor to disconnect power in an accident.

Some truck-conversions using Lead-acid batteries have been used as portable arc-welders. A 144v pack of large deep-cycle batteries can produce a LOT of power. Voltages for full-conversion EV's run 72 to 144+ volts, with controllers sometimes able to handle over 1kA continous.