tags: kitchen science, recharge batteries, streaming video
This streaming video describes a quick and easy way to recharge your dead batteries -- for free (unless you consider the expense of nearly boiling them in the process). I am not entirely convinced that this will work, but on the other hand, it is an interesting example of "kitchen science" where you can actually test this experiment for yourself and report back here. [1:07]
I'm curious on how long the "recharged" batteries last. My guess is that you're just getting that last 5-10% of energy that's left over. They'll probably be (irrecoverably) dead again in a week.
I'll have to see if I can scrounge up some dead batteries to test with, but I'm almost entirely sure that this is wrong. Batteries produce charge because of an internal chemical reaction. Heating up the batteries (and providing a conductive environment, albeit a bad one, to connect the two terminals) will just speed up the chemical reaction and discharge your batteries more quickly, not run the reaction in reverse.
If it isn't a complete trick, at best it might be a case of increasing the reaction rate to squeeze the last bit of life out of your batteries. Kinda like how Uri Geller thought he could start dead watches with his mind, when in fact all he was doing was warming them enough with his hand to unstick the lubricant inside.
This does in fact work, sort of. I used to do something like this back in the '50s with carbon batteries, but instead of heating them in water I put them in front of a forced air heating duct overnight. I have no idea if this will work with modern batteries, though I suspect it will to some extent.
RM is right; you don't get a lot of extra life out of them.