The Pet Tutor® remote has a rechargeable battery. To recharge it, connect remote to a laptop with a USB cable. Send us a note if you need a replacement.
Another possible cause for a discharge of the remote is the sleep timer was disabled. This happens whenever the remote is plugged in to a USB device or charger. To reactivate the sleep timer just press button 1 a single time after removing the USB cable.
The details on battery care, maintenance, and replacement may be found in the Pet Tutor® manual, section title To Replace Batteries [manual link].