I finally read my Tracker IV's manual and noticed like all the others I've had that the manual says to ONLY use alkaline batteries and of course you know what I've been using. I haven't been able to find some of the posts on this question, so I'll ask the guy who knows-am I hurting my detector? It didn't the other 2 I had years ago. Oh-here's today's finds. My first ring-silver. Another $70 and I'll have it paid for. The medallion is a track medallion with track shoes with wings on them. I'm not so sure about this thing not being deep, as it was only a little weaker on a signal than my Silver umax I tested a find BEFORE I dug it up. Thanks, Dave.