Way back in 1997 the German Post Office did a big trial with Zinc-air batteries in delivery vans https://www.newscientist.com/article/mg15420863-500-germany-gre

Way back in 1997 the German Post Office did a big trial with Zinc-air batteries in delivery vans https://www.newscientist.com/article/mg15420863-500-germany-greens-its-postal-vans/ https://www.newscientist.com/article/mg15420863-500-germany-... Zinc-air only gets you around 180 Wh/Kg, while Aluminium-air manages around 1300 Wh/Kg. If the article is correct that Trevor Jackson has solved practical problems with the electrolyte, then it is time to dig out the results from the old German Post Office trial. Why did it go nowhere? If the main problem was simply that Zinc-air batteries were too heavy, then a practical Aluminium-air battery is a big step forward. If on the other hand the problems were to do with swapping and re-smelting, then Aluminium-air might be solving the wrong problem.