As anyone actually had their batteries changed yet,there as been different times branded about as to how long the batteries will last,I believe the Scottish fanciers have had there systems a few years before fanciers down here so I dont think they are due to be changed yet,I personally have Bricon when I asked Mark Palmer about the batteries in my clock as I was one of the first to have the system in my area,he asked me to check the code number on the clock and then said bring your clock in and instead of changing the batteries just gave me a brand new one,no charge,somehow I cant see Unikon doing that.