Would you like to live a world in which you never have to charge your phone again. May be scientists inspired by this venerable scientific curiosity could help you… In the foyer of the Clarendon Laboratory in the University of Oxford lies an electric bell named as Oxford Electric Bell or Clarendon Dry Pile which has been ringing continuously since 176 years and has been recognised as the longest-lasting battery in the world.
Termed as one of the world’s oldest experiments, still no one knows exactly why it’s lasted so long. The only way to find out what is inside for sure is when the battery ultimately dies as opening the device could potentially ruin an experiment to see how long it will last. Therefore researchers will have to wait until either the battery finally loses its charge or else the ringing mechanism breaks on its own from old age.
Oxford Electric Bell made by Watkin and Hill, an instrument-making firm in London, and purchased by Robert Walker, a professor at Oxford was first displayed in 1840, says a handwritten note attested by his grandson on the bell. Some accounts at Oxford University says the bell could have been started even earlier, in 1825. The Guinness Book of World Records has named its power source the “world’s most durable battery.”
It’s a dry pile battery, which is one of the first electric batteries invented by a Giuseppe Zamboni during 1800s. They use alternating discs of silver, zinc, sulfur, and other materials to generate low currents of electricity. Being a dry pile battery, it’s got a paste inside with a minimum amount of water needed for the electrolyte to work. The battery is covered with an insulating layer of molten sulphur, in order to protect against atmospheric damage (i.e. moisture),connected in series at their lower ends to two bells. It’s theorized that the interior contains thousands of discs made of manganese dioxide and zinc. Between the bells is suspended a metal sphere or ‘clapper’ about 4mm in diameter which is attracted alternately by the bells and transfers charge from one to the other due to an electrostatic force, maintained by the ringing of the bells. The process is repeated over again and again. The frequency of its oscillation is about 2Hz and so far the bell would have rung roughly 10 billion times, and probably more than that, calculations from the university suggest.
High humidity can cause the clapper’s movement to slow and even stop, but when the humidity drops the bell can begin again without external intervention. As the clapper strikes and rings one bell, the corresponding dry pile charges and electrostatically repels it. The clapper then swings toward the other bell, and the same thing happens.
While it needs high voltage to create motion, the sphere only carries a small amount of electricity to the alternating dry piles. Because there’s just little bits of energy being discharged through the process, the drain on the battery is very less, and this may be the reason for its long run..
Presently the voltage left in the battery is so low that the human ear can’t actually hear the ringing. Instead, the clapper oscillates back and forth between the bell constantly. A former researcher at the Clarendon Laboratory, A. J. Croft, described the apparatus in a 1984 paper for the European Journal of Physics. According to him, the battery pulls 1 nanoAmp each time it oscillates between the bell’s sides, which is an remarkably a low amount of current. But the voltage between the bells is 2 Kilovolts, according to guest host, Sally Le Page, in the latest video on TOM SCOTT’s you tube channel.
A similar type of dry pile batteries were used to power the infrared telescopes during World War II, because a portable, low-current electricity source was necessary. Croft further wrote that an Oxford physicist, inspired by the bell, is working to make a similar one to boost up the present era telescopes.
I think we’re probably not going to build a better battery than this at this point. The bell has been ringing nonstop under the glass since 18oos and no one can tell when it will stop, leaving behind a mystery to be solved… The lifetime of this battery should be incredible, and if scientists are correct, it should work for thousands of years and outlive us..