How about Al/air batteries?

[Glen M]

http://cat.inist.fr/?aModele=afficheN&cpsidt=14442338

Résumé / Abstract
Aluminum (Al)/air batteries have the potential to be used to produce power to operate cars and other vehicles. These batteries might be important on a long-term interim basis as the world passes through the transition from gasoline cars to hydrogen fuel cell cars. The Al/air battery system can generate enough energy and power for driving ranges and acceleration similar to gasoline powered cars. From our design analysis, it can be seen that the cost of aluminum as an anode can be as low as US$ 1.1/kg as long as the reaction product is recycled. The total fuel efficiency during the cycle process in Al/air electric vehicles (EVs) can be 15% (present stage) or 20% (projected) comparable to that of internal combustion engine vehicles (ICEs) (13%). The design battery energy density is 1300 Wh/kg (present) or 2000 Wh/kg (projected). The cost of battery system chosen to evaluate is US$ 30/kW (present) or US$ 29/kW (projected). Al/air EVs life-cycle analysis was conducted and compared to lead/acid and nickel metal hydride (NiMH) EVs. Only the Al/air EVs can be projected to have a travel range comparable to ICEs. From this analysis, Al/air EVs are the most promising candidates compared to ICEs in terms of travel range, purchase price, fuel cost, and life-cycle cost.

[Cybereye]

One problem with this type of battery is non-rechargeable. So bye-bye regenerate brake and needed to be replaced once the battery drained. It would needed to carry an extra battery as a spare tire.

http://en.wikipedia.org/wiki/Aluminium_battery

[Glen M]

I think that regenerative braking is better suited to capacitors anyway. As far as the inability to recharge, If the energy calculations are correct, I don't know if this is really a problem. Swap out the sacrificed Al anode and replace with a new one and recycle the aluminum oxide.

Whether it is more efficient that Jerry Woodall's use of Al is another question.

[NZDavid]

As a range extender it sounds like a good idea. Garages would adapt to swapping out the waste and replacing the anode, quick and simple.

It also has the advantage of not going off or evaporating like petroleum would. The efficiencies would need to come up to compete with batteries though, so only as a range extender for me.