Hello. It sounds like some dust or debris or an insect got into the smoke chamber of the alarm and the alarm mistook the debris for smoke. It is possible that vacuuming out the alarm around the back side edges of the alarm very thoroughly with the hose attachment of a vacuum cleaner or blowing out the alarm with a can of compressed air like keyboard cleaner around the back side edges very thoroughly might have flushed out any debris and restored the alarm to working. We recommend cleaning out all of your smoke alarms at least every 6 months to a year and at this point we would recommend cleaning out all of your other alarms as well as a preventative. If you have issues in the future, please contact us with the product in hand at 1-800-880-6788 and we are happy to figure out what is going on and how we can get the issue resolved.

Hello. What activates the battery is when you put the alarm onto the bracket for the first time, the bracket hits an internal switch and that turns on the battery. If you have issues in the future, please contact us with the product in hand at 1-800-880-6788 and we are happy to figure out what is going on and how we can get the issue resolved.