Americans use around 2 Billion disposable batteries a year, one of those numbers that’s big enough for most of us to have no actual concept of it, but it’s a lot. If you find yourself being a larger than normal part of this statistic the obvious solution would be to use a rechargeable battery.

Blue Spark Technologies produce printed carbon-zinc batteries, which are small, environmentally friendly and most importantly cheap enough to produce to make them viable. These batteries are also incredibly thin; their standard battery is 750 microns thick (that’s 0.75 of a mm), while their Ultra-Thin series of batteries can go as slim as 500 microns.