I have an old American Hunter Digital feeder that has been going strong for many years but recently the digital clock battery died rendering it useless. I called American Hunter and they told me the clock battery is not replaceable and to just purchase a whole new feeder. Not cool!!! I decided to see if I could figure out how to replace the small coincell battery attached to the clock's circuit board. Not sure if anyone is still using these old models so I won't go into to much detail unless someone needs to know. I was able to remove the NiMh coincell battery, solder some wires to the contacts and install a 1aa battery holder. It now works perfect again and runs off a 1aa replaceable NiMh battery.