InfiniLED Illuninates for Years
This tiny LED magnet runs for five years on a single coin cell battery.
LEDs are extremely efficient sources of light. They can even be used with a coin cell battery, draining these cells after a few days or weeks. After finding an experiment that explored optimization of perceived brightness versus power consumption, BelgianEngineer came up with the InfiniLED, and now the InfiniLED v2, which can function for much longer.
The second iteration of the device is now for sale on Tindie, and according the listing it should shine for up to five years when powered by a single CR2032 battery. It comes in a nice cylindrical plastic enclosure, which contains the PCB and coin cell, along with neodymium magnets to allow it to attach to metallic surfaces. The idea is that you could place it on a refrigerator or similar surface to keep yourself from bonking around the house at night, as a nightlight for a kid’s room, or anywhere else that just a tiny bit of constant lighting would suffice.
The five-year value is based on a current draw of around 5uA, or .000005A, measured with an AN8009 multimeter. The trick to its longevity is that it actually oscillates at 35Hz at a carefully chosen pulse duration, allowing for sufficient perceived lighting levels, while drawing such a minuscule amount of current.