# 55 lbs, 1000 mile battery



## PStechPaul (May 1, 2012)

That is certainly amazing and promising news. I wonder if the aluminum batteries can be "recharged" at local energy sources or even at home. I know they are not rechargeable in the usual sense, but if the process of reconstituting them is fairly simple then it may be feasible for a homeowner or at least perhaps for "fueling stations", and it may also spawn a "cottage industry" to create jobs.

The conversion of aluminum oxide to pure metal is part of the process of extraction from bauxite ore. The following link says that it takes 6-8 kWh to produce a pound of aluminum. And it takes 4-5 volts at 50,000 to 150,000 amps. It may be a challenge to design an efficient source of such current, but I have some ideas. One would be to charge a battery pack of 100 x 200 Ah Lithium cells and then reconnect them as 2S50P. That should give a continuous 10,000 amps so at 5C to 15C it would give what is needed. Otherwise it may require a huge synchronous rectifier made from, say, 500 MOSFETs rated 100 amps each. They have some with RdsOn of 0.001 ohm, so 500 in parallel at 50kA would 5000 watts (10 watts each), while delivering 250kW for electrolysis at 98% efficiency.

http://www.elmhurst.edu/~chm/vchembook/327aluminum.html

The truly rechargeable zinc-air battery is also an exciting possibility. This is more reason to hold off on lithium purchases and if nothing else the competition may slash lithium prices in a few years.


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## rochesterricer (Jan 5, 2011)

What role does the water that must be refilled every couple of hundred miles play in the function of this battery?


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## Ziggythewiz (May 16, 2010)

Part of the oxidation reaction.


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## dreamer (Feb 28, 2009)

Ziggythewiz said:


> The one application where I could see battery swapping being practical: Roadtrips.
> 
> If they can ever get the net cost of these to $100 or less it'd take EVs from 80% to 99% viable.
> http://www.gizmag.com/phinergy-metal-air-battery/26922/


I'm not sure why they think it would be best used as a range extender for an EV with a conventionally recharged battery pack. 

People are accustomed to stopping for fuel every few hundred miles, so exchanging 25 plate modules at a Redbox-style vending machine every few hundred miles seems like a bargain compared to spending an additional $5K for a conventional battery pack that has to be charged at home and is also going to add weight to the vehicle.


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## ndplume (May 31, 2010)

The comment that these are more like fuel cells seems more accurate (not that it matters).

Even though there are good cases for using LiFeOn with and without a BMS, I think all commercial vehicle systems have them. Using this type of power system, where the plan is to run from 100% to 0%, it seems that all BMS effort/engineering would be unnecessary. That would simplify the electricity generation and remove the costs of the BMS from the pack and the vehicle. In addition, it would eliminate the cost/weight of an onboard charger as well.

THAT is the right direction.

Now back to Ziggy's $100 question...


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## Ziggythewiz (May 16, 2010)

dreamer said:


> I'm not sure why they think it would be best used as a range extender for an EV with a conventionally recharged battery pack.
> 
> People are accustomed to stopping for fuel every few hundred miles, so exchanging 25 plate modules at a Redbox-style vending machine every few hundred miles seems like a bargain compared to spending an additional $5K for a conventional battery pack that has to be charged at home and is also going to add weight to the vehicle.


It's usually far more economical to own something than to rent/lease. As a rare event a battery swap is a great idea, for daily use not so much. You'd still spend that $5k, just every 2 years instead of 8-10.


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