In the age of digital devices, it seems like everything you own needs constant charging. Between your smartphone, laptop, computer accessories, tablets, and other essentials, keeping the lights on, so to speak, is a hassle. Constantly replacing batteries is also pretty expensive over time.
Even if you use rechargeable batteries, they eventually need to be thrown out – the EPA has said that every year American’s throw away three million batteries per year, which translates to 180,000 tons of waste. This amount alone is enough to cycle the earth six times.
To help fix this problem, a team of nine out of Australia has developed Hydra-Light, a smartphone charger and lamp powered by salt water. Users simply fill the water chamber with seawater or tap water mixed with table salt. From there, the light will run and power will be provided.
At a high level, the lamp works by using a galvanic battery which has electrodes on each end. When submerged in salt water, the battery undergoes chemical reactions which generate electricity.
In the case of the Hydra-Light, the battery cells are made of two parts which are easy to replace; the outer cylinder and the internal cell. Unlike batteries which decrease output as they wear out, the rods within the Hydra-Light have constant output until the battery eventually dies. The other major difference from traditional batteries is that galvanic cells shrink in size and turn into harmless sediment as they’re used.
The bulbs within the Hydra-Light have a runtime of 250 hours and can be stored dry for up to 25 years. The only required maintenance is occasionally rinsing the power rods and adding new salt water – power rod replacement only takes a few seconds.
In addition to the light, some versions of the Hydra-Light have standard USB and 2.5mm jacks for charging external devices, like a smartphone or Bluetooth speaker. In addition to the internal light, the device also includes a 3 LED accessory lights powered by a headphone jack.
Hydra-Light successfully raised $39,430 (150% of their goal) from 453 backers over the course of their Kickstarter campaign, and expect to start shipping in July 2016. The light is currently available for pre-order on the company website with a starting price of $44. The version with smartphone charging support sells for $58. The additional power rods cost $12 for a pack of two.
There is an Instructables guide out there to help you make your own salt water night light, but this team seems to be on top of things, and the only thing nearly as good as saving the environment is saving your time. For under $60, it’s probably worth a peek.
