Remove the battery cover on the underside of the smart base unit.
Remove the old batteries and allow the smart base unit stand without batteries for 3 minutes before inserting new ones (this lets the base unit turn off completely before inserting new batteries).
Insert new batteries (3x AA batteries) making sure they are inserted the correct way round.
Always use the same type of the batteries, do not combine new batteries with old ones.
If the exchange went well, you will hear a beep. If you do not hear a beep, remove the batteries, wait 3 minutes, and insert the new batteries again, making sure that they are inserted the correct way round.
After a successful exchange, close the battery cover securely, insert the screw, and attach the base unit back to the bowl. Then you can fill the bowl with food or water.