MetalCell Battery can be Recharged with Salt Water or URINE
A new battery from South Korea is using some old tricks to make modern life easier. A South Korean company is replicating the process used by the 2,000 year old Baghdad Battery to make a modern battery which uses magnesium plates that can be recharged with salty water -- even urine contains enough sodium to do the trick. The MetalCell battery was designed originally for military field applications and can be activated when needed by adding a salty solution. The sodium reacts with the magnesium plates inside the MetalCell to create a low voltage power supply sufficient to run a laptop for four hours, and can be recharged with fresh saltwater until the magnesium eventually deteriorates.
The MetalCell comes in two models, a disposable version that costs around $120 and a standard field battery that is $200 and comes with salt tablets. The sodium in the salt oxidizes the metals, creating an electrical charge when it is exposed to water -- or urine. This process will eventually corrode the plates, which can then be replaced with fresh magnesium plates. The MetalCell battery can be left for years in a remote area and charged up when needed.