We all know that you can stick copper and zinc in an acid and make a battery. And the classic demonstration of this is with a lemon. YouTuber [NorthSurvival] takes this to an extreme — starting a fire by shorting his lemon battery across some steel wool. (Video embedded below.)
Now calling this a “survival tip” is pushing it. A lot. When’s the last time you went camping with a bunch of zinc and copper nails, much less a supply of fresh lemons? It might be easier to put some matches in a waterproof canister, or just bring a lighter. But when the zombie apocalypse comes, and all the lighters are used up, the man with a lemon tree will be a millionaire.
Seriously, though, this demo made us question a few assumptions. First, when people do the potato- or lemon-battery experiment, they often use multiple lemons. Why? Hooking the pins up like [NorthSurvival] did in series seems like a no-brainer after the fact.
And the lemon seems to be putting out a fair amount of juice (Amperes, that is). We’ve got to wonder — what is the short-circuit current of a lemon battery? And why haven’t we seen specs anywhere? What kind of “science education” experiment is this anyway, without measurements?
So we’re going to find some copper and zinc, and measure the current ourselves. And maybe parallel some lemons up if need be. How many lemons will it take to build a spot-welder?
[Editor’s (totally redfaced) Note: So we called for measurements, and people came up with them in the comments. The current coming out of a lemon battery is milliampy, which means that this video is a fake. Sharing the electrolyte, unless there’s more structure in the lemon than we know, should short-circuit it rather than produce more voltage, certainly at any useful current level. It’s a hoax, and we got hoaxed.]