I've purchased several types of battery operated candles, and I wanted these votives (they are not mini pillars) to compliment a couple of large pillar sets that also have a  hour timer. They came with internal batteries which have already gone dead. My other sets have been burning for 5 hours every night over the past 4 months, and only required one battery change. I'm disappointed with the mini set, but I guess I'll try to open then and see if the battery can be replaced.