A colleague recently brought the Hydra Light to our attention, a personal flashlight and charging station that runs on an electrolyte battery. While this design is patent pending, the basic technology behind it is as old- or older- than the pyramids. There is evidence that electrolyte batteries were known in ancient Persia and Egypt, and possibly across the ancient world. The windowless pyramids were lit with electric lights.
But how do electrolyte batteries work?
When most people think of electrolytes, they think of the minerals in Gatorade that help athletes rehydrate after strenuous exercise. Basically, electrolytes are salts dissolved in a solution, usually water, which can carry an electrical charge. Using two electrodes (zinc and copper, for example), a connecting wire and an electrolyte solution, a charge can be set up to form a battery. Any fruit or vegetable can be used for this purpose, and metal workers of the ancient world designed a ceramic, asphalt and metal battery that used an unknown electrolyte solution- perhaps salt water…the same electrolyte solution the Hydra Light uses.