New mic batteries

I changed batteries in the Shure lapel mic today. It went dead last week in the middle of my sermon (I just switched to a hand-held mic). I don't know if I forgot to record when the batteries were last changed, or if it actually was in August. If so, this batch lasted longer than usual. Seems like we can usually only get three months out of them. At any rate, hopefully I will not go dead today.