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At Oxford, a Battery That's Lasted 175 Years -- So Far
sarahnaomi writes There sits, in the Clarendon Laboratory at Oxford University, a bell that has been ringing, nonstop, for at least 175 years. It's powered by a single battery that was installed in 1840. Researchers would love to know what the battery is made of, but they are afraid that opening the bell would ruin an experiment to see how long it will last. The bell's clapper oscillates back and forth constantly and quickly, meaning the Oxford Electric Bell, as it's called, has rung roughly 10 billion times, according to the university. It's made of what's called a "dry pile," which is one of the first electric batteries. Dry piles were invented by a guy named Giuseppe Zamboni (no relation to the ice resurfacing company) in the early 1800s. They use alternating discs of silver, zinc, sulfur, and other materials to generate low currents of electricity.
Well, put a AA in a box and come back in 175 years, and try it out. Then we'll see how impressive that is.
> 1 nanoamp is so tiny that it may be being recharged from the environment somehow.
At that rate it doesn't need any recharging. A continuous 1 nanoamp draw (it doesn't make sense to say it draws 1 nanoamp per oscillation because amperage is a rate not a quantity) would discharge a small 1 Amp-Hour battery over one billon hours, or 114,000 years. The fact that it hasn't discharged through interal leakage is pretty impressive though.