Battery life really only lasted about a month but it only took 2 weeks of my 3 year old wearing it for it to get her fully potty trained! We were at our wits end of trying literally everything for the past year until I finally tried this watch. Whenever the song would play (I had it set for 30 minute intervals), we would make a huge deal and yell "potty time!" And we would all get up and dance and get her to the potty. There were a few days where she didn't want to wear the watch but we just kept making it cool and exciting for her to wear until the accidents got less and less. Definitely worth every single penny.