Awesome Junk Batteries

There have been some advances in batteries that have not made it into mass production because manufacturing a 1-off in the lab is quite a different thing than having machines make millions a day in a factory.

But what if a battery was simple enough to be made by hand? Sure a person would have to put in some sweat equity, but if you really wanted an inexpensive battery there are a lot of people that would be willing to trade time and effort for a battery that worked nearly as well as what they could buy. Especially considering the best prices on a Lead Acid battery bank for a good sized solar install can easily run into the thousands of dollars.

And what if you could even, with a little more effort, make this battery from scrap materials? For example, instead of a scraper (a person who collects and recycles scrap for money) delivering their steel and brass to a scrap collector, one could have the scraper deliver it to them by offering a little better price.

And having mentioned steel and brass, those are the two metals that the researchers at Vanderbilt University have proposed for their scrap battery. Cary Pint is an assistant professor of mechanical engineering.

Pint said:

“We’re forging new ground with this project, where a positive outcome is not commercialization, but instead a clear set of instructions that can be addressed to the general public. It’s a completely new way of thinking about battery research, and it could bypass the barriers holding back innovation in grid scale energy storage,”

This sounds interesting, but what about performance? They claim a steel-brass battery can store about 20 Wh/kg and deliver 20,000 W/kg. That's not too bad for a homemade battery. Lead acid will give you more like 35-40 Wh/kg and deliver a whopping 20 W/kg...

Wait a second.

Lead acid batteries can deliver a lot of current. But supposedly this steel-brass battery can deliver a great deal more. Barring a typo, I'm impressed. Even at not quite 1/2 the capacity a steel-brass battery just might pay off. Especially at scrap prices.

So here's what might be wrong with this idea. Since the energy density is rather low, it's going to take almost 2 times as much battery to make a battery bank. The logistics of that seem a little daunting. Also, they said they could get 5000 cycles out of this chemistry, but they didn't tell us how deeply these can discharge without damage.

So we need a little more information, but it still sounds like something worth looking at.