Metrotech is usually a utility locating detector.... I used them for 15 years locating telecom cables....Over the years I have owned many different detectors beginning with Metrotech and I know better than to leave the batteries in one for any length of time. I have seen what it can do. I just recently fixed one for my nephew because of
batteries leaking. That can really make a mess. He was lucky, it only ruined the battery holder contacts plus the part that clips on to the battery pack. Had to cut the wire back a short ways too.
I suggest you look for a single box detector, it will be very hard to get yours repaired if they are out of business and expensive, better off putting that money on a single box detector..