It depends on where you buy them. Dollarstore tealights can stop working on a whim. Sometimes they are good.Most of the time the battery cover breaks and won't keep good contact. One's we've bought at Wallmart and were used last Halloween, still work for this Halloween. I'm going to guess there are at least 20 hours of light time in them.Very nice Lynn, another method of a PVC candle build, like it and now I have a couple of ideas on mixing in various types. Question: How long do the flicker tea lights last before requiring a new battery?