Hurricanes, earthquakes, elected officials -- there are plenty of legitimate reasons to prepare for the end of civilisation as we know it, and if the world's supply of batteries ever runs out, you'll be glad you had this emergency LED lamp tucked away in your doomsday shelter.
Instead of trying to dig up a fresh pair of AAs when the power goes out, all that's needed to power Hitachi Maxell's Mizusion lamp for about three days is a mix of salt and water. The ingredients work alongside oxygen in the air and a replaceable magnesium "power bar" to create positive and negative electrodes, which in turn generates electricity.
If you buy it from a foreign supplier like this one that imports products from overseas, you can expect to pay around $76 for the lamp, which is quite a markup. But if purchased in Japan, the emergency lamp is a little more reasonable at $34, with the magnesium refills costing around $12 each. Happy apocalypse prep!