Hello everybody. This is my first post with any engineer's forum.

Our dilemma: We require a low current LED to blink until a small button-cell battery goes dead. The LED will not be activated until 2-3 years pass. I assume that we cannot use a circuit that uses power for the years needed. However, I could be mistaken about my guess. I specifically require power to make the LED blink after the time period mentioned for a week or two, or perhaps as long as the power source lasts. Here are the qualifications:

  1. Can a button-cell power a circuit for two years, and then blink an LED for several days or weeks later on time?
  2. Do I use a countdown circuit? And will that use power up to and including the LED blinking?
  3. This needs to be done at a low expense to me because we are a nonprofit and our budget is small.
  4. I need to make 50 pcs. for a trial, then hundreds.
  5. I will work with volunteers here in CA, at my workshop for assembly and shipping. No other-country assembly necessary.
  6. How long would a button-cell battery last over 2 yrs.? Or, more? Is it possible? Do I need Lithium which will increase the cost of materials and perhaps be a potential fire hazard?
  7. This device will be used by the poor and struggling peoples that only need to see the blinking LED. No switch, no connectors, or anything that a person needs to do for this device to do its job. It must be 100% self-reliant.
  8. Not solar powered.
  9. Is there a material or semiconductor that will dissolve in the time needed that will cause a current to flow?
  10. Is this materials science? Or chemical science?
  11. My major is Nonprofit Business Administration, not electronics. We deeply appreciate any help and assistance. I will keep you or your organization informed of our progress and updates from field tests. You can even choose a name for the device, or sponsor the use of the device through yourself, or your organization. Often times, businesses and corporations have a Social Responsibility Program that loves to share information. We depend on outside help and we treat all help as tremendously valuable and precious.
  12. Thank you very much for your time and effort.